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EK-DLV11-OP-001

June 1977

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Document:	DLV11-E and DLV11-F Asynchronous Line Interface User's Manual
Order Number:	EK-DLV11-OP
Revision:	001
Pages:	115
Original Filename:	http://bitsavers.org/pdf/dec/qbus/EK-DLV11-OP-001_DLV11-E_and_DLV11-F_Asynchronous_Line_Interface_Users_Manual_Jun77.pdf

OCR Text

DLV11 -E and 0 LV11-F
asynchronous
line interface
user's manual

EK-DLV11-0P-001

DLV11-E and DLV11-F
asynchronous
line interface
user's manual

digital equipment corporation • maynard, massachusetts

1st Edition, June 1977

The material in this manual is for informational
purposes and is subject to change without notice.
Digital Equipment Corporation assumes no responsibility for any errors which may appear in this
manual.
Printed in U.S.A.

This document was set on DIGITAL's DECset-8000
computerized typesetting system.

The following are trademarks of Digital EqUipment
Corporation, Maynard, Massachusetts:
DEC
DECCOMM
DECsystem-lO
DECSYSTEM-20

DECtape
DECUS
DIGITAL
MASSBUS

PDP
RSTS
TYPESET-8
TYPESET-ll
UNIBUS

CONTENTS
Page
CHAPTER 1

INTRODUCTION

1.1
1.2
1.3
1.4

PURPOSE AND SCOPE . . . . .
OPERATING FEATURES
MODULE SPECIFICATIONS ..
MAINTENANCE . . . . .

CHAPTER 2

GENERAL DESCRIPTION

2.1
2.2
2.3
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10
2.3.11
2.3.12
2.3.13

GENERAL . . . . . . .
MODULE FUNCTIONS
CIRCUIT FUNCTIONS
General
Bus Interface
I/O Control Logic
Control/Status Registers
Data Buffers . . . . .
Receiver Active Circuit
Interrupt Logic
Baud Rate Control
Break Logic . . . .
Maintenance Mode Logic
DLVll-E Peripheral Interface
DLVll-F Peripheral Interface
DC-to-DC Power Inverter

CHAPTER 3

INSTALLATION

3.1
3.2
3.3
3.4
3.4.1
3.4.2

GENERAL
.... .
CONFIGURATION . . . .
MODULE INSTALLATION
MODULE CHECKOUT . . . . . . . . . . . .
DLVll-E Checkout . . . . . . . .
DLVll-F Checkout . . . . . . . . . . .

CHAPTER 4

PROGRAMMING

4.1
4.2
4.3
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.5
4.6

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
DEVICE REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . .
4-1
INTERRUPTS . . . . . . . . . . . . . . . .
. ........ .
4-9
TIMING CONSIDERATIONS . . . . . . . .
· 4-10
Receiver . . . . . . . . . . . . . . . .
· 4-10
Transmitter . . . . . . . . . . . . . .
· 4-10
BREAK Generation Logic . . . . . . . . . . . .
· 4-10
. . . . . . . . . . .
System Reset Timing
· 4-10
PROGRAMMING EXAMPLES
.......... .
. . . . 4-10
. . . . . . . . . . .
PROGRAMMING NOTES.
. . . . 4-18
iii

1-1
1-1
1-3
1-3

2-1
2-1
2-3
2-3
2-3
2-4
2-4

2-7
2-7
2-7
2-8
2-8
2-8
2-8
2-9
2-9

3-1
3-1
3-1
· 3-11
· 3-15
· 3-15

CONTENTS (CONT)
Page
CHAPTERS

DETAILED TECHNICAL DESCRIPTION

5.1
5.2
5.2.1
5.2.2
5.3
5.3.1
5.3.2
5.3.3
5.4
5.4.1
5.4.2
5.4.3
5.5
5.5.1
5.5.2
5.6
5.7
5.7.1
5.7.2
5.7.3
5.7.4
5.8
5.8.1
5.8.2
5.8.3
5.8.4
5.9
5.9.1
5.9.2
5.10
5.11
5.12
5.12.1
5.12.2
5.13

GENERAL
..... .
BUS INTERFACE . . .
Address Decoding
Vector Addressing
I/O CONTROL LOGIC
Input Operation .
Output Operation
Vector Operation
CONTROL/STATUS REGISTERS
CSR Data Flow
Input Operation .
Output Operation
DATA BUFFERS . . .
Receiver Operation
Transmit Operation
RECEIVER ACTIVE CIRCUIT
INTERRUPT LOGIC . . . . .
DLVII-E Receiver Interrupts
DLVII-F Receiver Interrupts
Transmitter Interrupts
Interrupt Transactions
BAUD RATE CONTROL
Program Control
Jumper Control
External Control
Clock Selection
BREAK LOGIC . . .
Receive Operation
Transmit Operation
MAINTENANCE MODE LOGIC
DLVII-E PERIPHERAL INTERFACE
DLVII-F PERIPHERAL INTERFACE
EIA Data Leads Only Operation
Current Loop Operation .
DC-TO-DC POWER INVERTER

APPENDIX A

IC DESCRIPTIONS

A.l
A.2
A.3
A.4
A.4.1

DC003 INTERRUPT LOGIC
DC004 PROTOCOL LOGIC .
DC005 TRANSCEIVER LOGIC
UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER
Receiver Operation

5-1
5-1
5-1
5-1
5-2
5-3
5-6
5-7
5-7
5-8
5-11
5-11
5-12
5-13
5-15
5-16
5-16
5-17
5-18
5-19
5-19
5-20
5-20
5-23
5-23
5-23
5-23
5-24
5-24
5-25
5-26
5-28
5-28
5-29
5-29

A-I
A-I
A-I
A-19
A-19

CONTENTS (CONT)
Page

A.4.2
A.5

Transmitter Operation . . . . . . .
5016 DUAL BAUD RATE GENERATOR

APPENDIX B

WIRE WRAP INSTRUCfIONS

B.l

PURPOSE . . .
DEFINITIONS
CONNECTIONS
PROCEDURE .

B.2
B.3
B.4

A-21
A-29

B-1
B-1

B-2
B-3

FIGURES
Figure No.

2-1
2-2

2-3
3-1

3-2
3-3
3-4
3-5

4-1
4-2
4-3

4-4
4-5
4-6
4-7
5-1

5-2
5-3
5-4

5-5
5-6
5-7
5-8
5-9
5-10
5-11

5-12
5-13

Title

Page

Interfacing Examples
. . . . . . . . . . . . . .
DLV11-E and DLV11-F Data Flow, Simplified Block Diagram
DLV11-E and DLV11-F Functional Block Diagram
DLV11-E Jumper Locations
DLV11-F Jumper Locations
DLV11-E Cabling Example
DLV11-F Cabling Examples
Typical Backplane Configuration
DLVI1-E RCSR Bit Assignments
DLVl1-F RCSR Bit Assignments
DLV11-E and DLV11-F RBUF Bit Assignments
DLV11-E and DLV11-F XCSR Bit Assigments
DLV11-E and DLVl1-F XBUF Bit Assignments
DLV11-F Programming Example
Serial Data Format
.......... .
DLV11-E and DLV11-F Addresses
DLV11-E and DLV11-F Interrupt Vectors
I/O Control Logic, Block Diagram
Data Input Timing . . . . .
Data Output Timing . . . .
DLVl1-E RCSR Data Flow
DLV11-F RCSR Data Flow
DLVll-E and DLV11-F XCSR Data Flow
Control/Status Registers During DATI
Control/Status Registers During DATO or DATOB
UART Signal Flow . . . . . . . . . . .
DLV11-E and DLV11-F RBUF Data Flow
DLVl1-E and DLVl1-F XBUF Data Flow

2-2
2-3
2-5
3-2
3-3

3-9
3-10
3-11
4-2

4-5
4-6
4-7
4-8

4-15
. 4-18

5-2
5-2
5-4
5-5
5-6
5-8
5-9
5-10

5-11
5-12
5-l3
5-14

5-16

FIGURES (CONT)
Figure No.
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
A-I
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-lO
A-ll
A-12
A-13
A-14
B-1
B-2
B-3
B-4

B-5
B-6

Title
Receiver Active Circuit
Interrupt Vector Signal Flow
..... .
Interrupt Timing
Baud Rate Control Signal Flow
Break Logic Receive Signal Flow
Break Logic Transmit Signal Flow
Maintenance Mode Logic
DLVII-E Peripheral Interface Signal Flow
Data Lead Only Interface . . . . . . . .
20 rnA Transmitter and Reader Run Circuit
Active Receive 20 rnA Current Loop
Passive Receive 20 rnA Current Loop
Interlock Jumper Data Flow
DC003 Simplified Logic Diagram
DC003 "A" Interrupt Section Timing Diagram
DC003 "A" and "B" Interrupt Section Timing Diagram
DC004 Simplified Logic Diagram . . . . .
DC004 Timing Diagram . . . . . . . . . .
DC004 Loading Configuration for Table A-2
DC005 Simplified Logic Diagram
DC005 Timing Diagram . . . . .
DART Data Format . . . . . . .
DART Receiver - Block Diagram
DART Transmitter - Block Diagram
DART Pin Locations
5016 Block Diagram . . . . . . . .
5016 Pin Locations . . . . . . . .
Solderless Wrapped Connection on Wire Wrap Pin
Full Turn . . . . . . .
Half Turn
Two Levels of Wire Wrap
Defective Wire Wraps
Loading the Wire Wrapping Kit

Page
5-17
5-18
5-19
5-21
5-25
5-25
5-26
5-27
5-28
5-30
5-31
5-31
5-32
A-3
A-5
A-6
A-9

A-13
A-14
A-16
A-17
A-19
A-20
A-21
A-22
A-29
A-30
B-1
B-2
B-2
B-3
B-4

B-6

TABLES
Table No.
I-I
3-1
3-2

Title

Page
1-2
3-4
3-6

Feature Comparison
Jumper Definitions
Baud Rate Selections

TABLES (CONT)
Table No.
3-3
3-4
3-5
3-6
3-7
3-8
4-1
4-2
4-3
4-4
4-5
4-6
4-7

5-1
5-2
5-3
A-I
A-2
A-3
A-4
A-5
A-6
A-7

Title
Data Bit Selections
Jumper Configuration When Shipped
Module Application Examples . . . .
DLVll-E 40-Pin Header Connector Pinning
DLVll-F 40-Pin Header Connector Pinning
DLVll-E and DLVll-F Edge Connector Pinning
Register Addresses for Console Interfacing
DLVll-E RCSR Bit Assignments . . . . . . .
DLVll-F RCSR Bit Assignments . . . . . . .
DLVll-E and DLVll-F RBUF Bit Assignments
DLVll-E and DLVII-F XCSR Bit Assignments
DLVll-E and DLVll-F XBUF Bit Assignments
DLVll-E Programming Example
Register Selection . . . . . . . . . . . .
Byte Selection (Output Operations Only)
UART Clock Sources . . . . . . . . . .
DC003 Pin/Signal Descriptions . . . . .
DC004 Signal Timing vs Output Loading
DC004 Pin/Signal Descriptions
DC005 Pin/Signal Descriptions
UART Pin Functions
5016 Selectable Frequencies
5016 Pin Functions

vii

Page
3-6
3-7
3-9
3-12
3-13
3-14
4-1
4-2
4-5
4-6
4-7

4-8
4-11
5-3
5-7
5-24
A-7
A-II
A-14
A-18
A-23
A-30
A-3l

CHAPTER 1
INTRODUCTION

1.1 PURPOSE AND SCOPE
The DLVII-E and DLVII-F are asynchronous line interface modules that interface the LSI-II bus to
any of several standard types of serial communications lines. The modules receive serial data from
peripheral devices, assemble it into parallel data, and transfer it to the LSI-ll bus. They accept data
from the LSI-ll bus, convert it into serial data, and transmit it to the peripheral devices. The two
modules differ in that the DLVll-E offers full modem control, whereas the DLVll-F supports either
20 rnA current loop or EIA-standard lines, but does not include modem control.
This manual describes these modules to the user. It treats the two modules together for those functions
common to both, and separately for those areas in which they differ. It is assumed that the reader has a
general familiarity with the operation of the LSI-II computer and with the requirements of the peripheral equipment. Refer to Microcomputer Handbook, EB 06583 76, for detailed information about the
LSI-ll.

1.2 OPERATING FEATURES
Each asynchronous line interface is constructed on a single 21.6 cm X 122.7 cm (8.5 in X 5.0 in) dualheight module. The module mounts in any slot in the LSI-II's backplane. Both the DLVI1-E and the
DLVll-F have the following features:
• Jumper- or program-selectable crystal-controlled baud rates: 50, 75, 110, 134.5, 150,300,600,
1200, 1800,2000, 3600,4800, 7200, and 9600.
• Provisions for user-supplied external clock inputs for baud rate control.
• Jumper-selectable parity and data bit formats.
• LSI-ll bus interface and control logic for interrupt processing and vectored addressing of
interrupt service routines.
• Control, status, and data buffer registers directly accessible via processor instructions.
• Program and peripheral connector plug compatible with the PDP-II DLII series of asynchronous line interface modules.
The DLVll-E is designed to interface data sets (modems with control capability) such as Bell models
103, 202C, and 202D.
The DLVII-F is designed for either 20 rnA current loop equipment or EIA-standard "data leads only"
(no modem control) operation. Flexibility is achieved by the use of wire wrap jumpers. Table
1-1 compares the features of the DLVll-E and DLVll-F with those of the DLVll and the DLll
series. Refer to Paragraph 4.4, Timing Considerations, for further information.

1-1

Table 1-1

Feature Comparison

(NOTE: X indicates feature available.)
Features

DLll-A
throughD

DLll-E

DLVll

Programmable Baud Rates
(Write Only Bits)
Modem Control

DLVll-F

DLVll-E

EIA "Data Leads Only"

20 rnA Current Loop

Jumper Selectable
Active or Passive
20 rnA Current Loop
Error Flags

BREAK Generation Bit

Receiver Active Bit

Maintenance Bit
On-board Clocks for
Split Speed Operation

Halt on Framing Error

Boot on Framing Error
UART Cleared by INIT

UART Cleared by DCOK

No Trap on Write
to RBUF

1.5 STOP BITS

Modem Status Bit

1-2

1.3 MODULE SPECIFICATIONS
The following specifications and particulars are for informational purposes only and are subject to
.
change without notice.
Physical Characteristics
Dimensions
Circuit Card
Length:
Height:
Width:

Circuit Card Plus Handles

21.6 cm (S.5 in)
12.7 cm (5.0 in)
1.3 cm (0.5 in)

22.S cm (S.9 in)
13.2 cm (5.2 in)
1.3 cm (0.5 in)

Cable Connection

One 40-pin header connector

Mounting Requirements

Plugs directly into any dual-height slots on the
LSI-II backplane or LSI-II expansion box

backplane.
Electrical Characteristics
Module Type
DLVll-E: MS017
DLVll-F: MS02S
Power Requirements
1.0 A (nominal) @ +5 V ±5%, 5.0 W
150 rnA (nominal) @ +12 V ±5, I.S W
LSI-ll Bus Loading
Presents one bus load.
Environmental Characteristics
Temperature
Operating
Nonoperating

5° C to 50° C (41 ° F to 122° F)
-40° C to 66° C (-40° F to 151 ° F)

Humidity (Operating and Nonoperating)
10% to 95%, maximum wet bulb 32° C
(90° F) and minimum dew point 2° C (35° F)
Altitude
Operating
Nonoperating

2.4 km (S,OOO ft)
9.1 km (30,000 ft)

1.4 MAINTENANCE
This manual explains the normal operation of the asynchronous line interface modules. This information and the diagnostic maintenance programs will aid the user when analyzing trouble symptoms to
determine necessary corrective action. A set of engineering drawings is available for each of the two
modules. Refer to DLVll-E Asynchronous Line Interface, Circuit Schematics (DIGItAL part number D-CS-MSOI7-0-1) or DLVI1-F Asynchronous Line Interface, Circuit Schematics (DIGITAL part
number D-CS-MS02S-0-1).

1-3

Signal names in the DLV11-E and DLV11-F print sets are in the following basic form:
SOURCE

SIGNAL NAME

POLARITY

SOURCE indicates the drawing number of the print set where the signal originates. The drawing
number of a print (K-3, K-4, K-5, etc.) is located above the title block.
SIGNAL NAME is the proper name of the signal. The names used in the print set are also used in
this manual.
POLARITY is either H or L to indicate the voltage level of the signal: H ~ +3 V; L ~ ground.
As an example, the signal:
(K-3) INIT H
originates on sheet K-3 of the drawings and means "when INIT is true, this signal is at approximately +3 V."
LSI-II bus signal lines do not carry a SOURCE indicator. These names represent a bidirectional wireORed bus. As a result, multiple sources for a particular bus signal exist. The LSI-II bus signal names
begin with a "B" for "bussed."
The D LV 11-E module is shipped with an H3I5 modem test connector included. This is plugged into
the interface cable in place of a data set when running maintenance programs. The DLVII-F does not
use this test connector.
A paper tape diagnostic maintenance program is shipped with the module for checkout and maintenance. The following programs are available:
DLVII-E: MAINDEC-11-DVDVA
DLV11-F: MAINDEC-11-DVDVC

1-4

CHAPTER 2
GENERAL DESCRIPTION

2.1 GENERAL
The DLVll-E is designed to interface equipment that transmits and receives data over communications lines and conforms to EIA Standard RS232C and CCITT Recommendation V.24. The
DLVII-E is used by the program to control a communications data set through the use of control
signals and handshake sequences.
The DLVll-F supports either EIA-compatible data lines or 20 rnA current loop data lines. When
configured for EIA support, the DLVll-F transmits and receives bipolar levels over the data lines to
the device. This operation does not include control lines. When configured for 20 mA current loop
operation, the DLVII-F can support either active or passive current loop devices. Figure 2-1 illustrates
several applications of the modules.
2.2 MODULE FUNCTIONS
The DLVll-E and DLVll-F asynchronous line interface modules take data from the LSI-ll and
convert it to the speed, character format, and signal levels required by the user's peripheral devices.
Conversely, they assemble inputs from the peripheral devices into the format required for transfer to
the computer. The computer program can address any of four registers in the interface modules to
transfer data or status information. It can also enable the interface modules to generate interrupts.
When a peripheral device requires service, the interface module will, if enabled, interrupt the program
and vector to the necessary service routine.
Data passes through three main circuits on its way to and from the peripheral device (Figure 2-2).
During computer output operations, parallel data is taken off the LSI-II bus by a bus interface circuit
and placed on the module's internal three-state bus. The data on the three-state bus enters a data
buffer, where it is serialized and formatted for the peripheral device. From there it goes to a peripheral
interface circuit that changes it from TTL to either EIA-compatible bipolar levels (DLVll-E or
DLVII-F) or 20 rnA current loop signals (DLVII-F only). The data then leaves the module on an
interface cable and goes to the user's peripheral device. Data coming into the computer from the
peripheral device goes through this process in reverse order.
The control functions within the interface module are carried out by circuits that handle I/O transfers,
interrupt requests, and control and status information. The DLVII-E interfaces control signals as well
as data between the LSI-ll and the peripheral. The extent of this interaction is determined by the
program and the type of perip.heral being supported.
The DLVll-E and DLVll-F also have a self-test function. When the computer program places the
module in the maintenance mode, parallel data travels through the bus interface and the data buffer, is
serialized, and then loops back through the data buffer, is converted back to parallel, and travels
through the bus interface to the computer to be checked for accuracy.

2-1

LSI-II BUS

EIA/CCITT
LSI-II BUS

INTERFACING A REMOTE TERMINAL

LSI-II BUS

INTERFACING A REMOTE LSI-II

EIA/CCITT
REMOTE COMMUNICATIONS via PRIVATE LINES
20mA

LSI -II BUS

EIA/CCITT
INTERFACING A LOCAL TERMINAL
INTERFACING A REMOTE PDP-II
11- 4958

Figure 2-1

Interfacing Examples
2-2

~~~~~~~~~~---------l

I
~

I
K
.. I
I
I
I

TTL
PARALLEL
LINES

....

BUS
ADDRESS AND DATA) INTERFACE

:::l
In
I

H
Ul

...J

TTLD~~:IAL

THREE-STATE
PARALLEL
LINES

DATA
LINESI

LINES

DATA
BUFFERS

•

IMAINT
MODE I
LOGIC

II'

I
PERIPHERAL
INTERFACE

CONTROL

CONTROL FUNCTIONS

I
"Ii

PERIPHERAL
DEVICE

I
I

__________________

I
I
I
I
I

~
11-4959

Figure 2-2 DLVII-E and DLVII-F Data Flow, Simplified Block Diagram

2.3 CIRCUIT FUNCTIONS
2.3.1 General
This section discusses the circuits on a functional level and is keyed to Figure 2-3. For a more detailed
coverage of circuit operation, refer to Chapter 5.
2.3.2 Bus Interface
The bus interface circuit performs three basic functions:
1.

It converts signal levels of data moving between the LSI-II bus and the interface module's
internal three-state bus.

It decodes the device address and produces an address match (MATCH H) signal.

It generates interrupt vectors and places them on the LSI-ll bus.

The LSI-II signals are standard TTL levels. The module's internal three-state bus, however, has three
signal conditions. It has TTL high and low states, and also a disabled state. When a bus interface
transceiver output is disabled, it goes to a high impedance condition that does not affect other devices
connected to the same line. This permits the lines to be used in both directions by high speed, low
power devices.
The bus interface is normally enabled to receive from the LSI-II bus. It can be switched to transmit
onto the LSI-II bus by either the I/O control logic or the interrupt logic. The signals received from the
LSI-II bus are ignored unless the address decoding function is enabled.

2-3

The bus interface circuit monitors LSI-II bus lines BDALOO L through BDAL15 L. It inverts these
signals and places them on three-state bus lines DATOO H through DAT15 H. If the information on
the BDAL lines is the address of a location in the upper 4K of addressing space, i.e., in the I/O page,
the LSI-II asserts BBS7 L. This signal enables the device address decoding function in the bus
interface.
To decode the address, the circuit compares BDAL03 L through BDAL12 L with address jumpers A3
through A12. If the states of the BDAL lines match the corresponding jumpers the user has installed,
the circuit sends MATCH H to the I/O control logic. MATCH H is a prerequisite for data
transactions.
The bus interface logic generates vector addresses under the control of the interrupt logic and the
vector address jumpers. The circuit creates two vectors; one for receiver interrupts and one for transmitter interrupts. The combination of VECTOR Hand VECRQSTB H from the interrupt logic and
the states of vector address jumpers V3 through V8 determines what vector will be placed on the LSI11 bus lines.
2.3.3 I/O Control Logic
The I/O control logic directs data transactions between the LSI-ll and the interface module. A data
transaction can be a word or a byte, a high byte or a low byte, an input or an output, or status
information or character information. The I/O control logic monitors the LSI-II bus lines to recognize what type of transaction is to be accomplished. It uses this information to control four device
registers. The registers are named after their functions as follows:

Receiver Control/Status Register
(RCSR)
Transmitter Control/Status Register
(XCSR)
Receiver Buffer
(RBUF)
Transmitter Buffer
(XBUF)
These four registers are described in subsequent paragraphs of this chapter.
An I/O operation begins with the LSI-ll addressing the interface module. The bus interface decodes
the address, asserts MATCH H to the I/O control logic, and places the address on the three-state bus
lines. The I/O control logic decodes the three least significant bits of the three-state bus lines (DATOO
H through DA T02 H) and the LSI-II bus control signals. The circuit develops register selection and
byte selection signals to enable the correct data paths between the computer and the appropriate device
register. It also controls INWD L, which determines whether the bus interface transceivers are transmitting or receiving. When data becomes available, the I/O control logic gates it to its destination
(from the LSI-II bus to the three-state bus for an output transfer, or from the three-state bus to the
LSI-II bus for an input transfer).
2.3.4 Control/Status Registers
The DLVII-E and DLVI1-F each have two control/status registers: the RCSR and the XCSR. The
computer writes control bits out of these registers and reads status bits in from them. The registers
consist of a series of latches, data selectors, and gating circuitry. During data transactions involving
control and status information, the I/O control logic enables the XCSR or RCSR to either latch in
control bits or gate out status bits.

When status information is to be read into the computer, the LSI-ll addresses the device register
containing the desired information. The bus interface and I/O control logic decode the address and
enable the contents of the selected register to be placed on the bus and transferred into the computer.
When control information is to be written out to the interface modules, the computer addresses the
device register that is to be loaded. The bus interface and I/O control logic decode the address and
enable the register to load the control information when it is placed on the bus.

2-4

PERIPHERAL
INTERFACE

DATA
BUFFERS

~ ~ E ~ ~ SERIAL IN I MAINTENANCE I...-r--------I ~ ~ ~ iii ~ 1+-------11MODE
k-,

7 ~ ~ %: : ~: sERIALouTa..;;;Lo;';G;;'lc~----'-ll

BUS
INTERFACE

~)
BBS7 L

~~
. . e_ i~!!a

DEVICE
ADDRESS
DECODER

VECTOR
ADDRESS
GENERATO.R

~DRES ~ECTOR
JUMPERS
A3-A12

/,;R:;;E::G~IS::T=;ER""'__~""'I

VECTOR H

TC~

I,R=E::C=EI=V~ER:-----S"'"\:=-1

i---l t

LOGIC
-12V

FE H

BREAK

t,."T"-~--.,,~rJ----'-'=--4-1 ~~~;~TlON

EIADATA
LEADS
tBOTH DLV11-E
ANDDLV11·F)

I----~-

20mACURRENT ~
LOOP AND
READER RUN
tDLV11~ ONLY) ......

MAINTH

CONTROLIST ATUS

I I
OC-TO-OC

POWER
INVERTER

+12V

'---

GENERATION

~r---~----t-~~---;:;;;::::~----t--r~----t-----~

:RANSM'TTER sl
CONTROllST ATUS

JUMPERS
V3-Va

:: ~::; ~

}=~.

1"~~~__,-~~__-t~I~N~W~D~L-----,

- "\ z~
--,/

THREE·,nATE BUS
TRANSCEIVERS

RBUS:R~AK ~

MATCHH

N
I

VECTOR H

VECRQSTBH

BSYNC L

1/0 CONTROL

BWTST L

LOGIC

"'----.-:-----11 1

~--...I.----,-I------.&....-I'-------.

BIAKI L

RECEIVER
JUMPERS

~~R::O-~R~3~~

BIROl

BlAKe L

BAUD RATE CONTROL

BRPLY l
BDOUT L

BDIN L

CONTROL
CIRCUITRY

TRANSMITTER
CHANNEL

DATA
FORMAT
JUMPERS

01 1 - - - - - - - - + - - - + - - - - - - - - 1

TRANSMITTER
JUMPERS

~TO~-~T~3____J

RECEIVER
CHANNEL

alNIT L

INTERRUPT LOGIC
BHALT L

BDCOK H

11-4960

Figure 2-3 DLVll-E and
DLVll-F Functional Block Diagram

Not all control and status bits are both read and write; some are read-only bits and some are write-only
bits. A detailed description of each bit is given with the programming information in Chapter 4.
2.3.S Data Buffers
The DLVII-E and the DLVII-F each have two data buffers: one for receive data (RBUF) and one for
transmit data (XBUF). Both data buffers handle data by bytes. The RBUF also holds error flag bits
pertaining to the status of the received data.
The data received from the peripheral device is transferred serially from the peripheral interface circuit
into a receive shift register in the data buffer. From there it is transferred in parallel to a holding
register. At the appropriate time, the buffer control circuitry places the parallel data, along with error
information, onto the module's internal three-state bus. The bus interface then transfers the data to the
computer.
Data to be transmitted to the peripheral device is taken off the three-state bus in parallel by the XBUF
and then shifted serially out to the peripheral interface circuit.
Both the RBUF and the XBUF provide "double-buffering" of the data. The buffering is double in that
the circuits each have both a serial shift register and a parallel holding register. This allows one character to be held while another is being moved into or out of the buffer.
2.3.6 Receiver Active Circuit
The receiver active circuit monitors the serial received data line from the peripheral interface and a
receiver done (RDONE H) status bit from the RBUF. The circuit generates a busy signal (RBUSY H)
to indicate that the receiver is active. This signal sets the RCVR ACT bit in the RCSR.
2.3.7 Interrupt Logic
When a peripheral device interfaced by a DLVll-E or DLVll-F needs service, the module can, if
enabled, interrupt the computer program and vector to a service routine. The interrupt logic can
initiate two types of interrupts: a receiver interrupt and a transmitter interrupt. These interrupts are
handled through separate receiver and transmitter channels.
For an interrupt transaction to occur, first the program sets the interrupt enable bit in the control/status register. Next, the interrupt logic recognizes the condition requiring service and asserts the
interrupt request line (BIRQ L) to the computer. When the interrupt is acknowledged by the computer, the interrupt logic enables the bus interface to place the vector on the bus lines.
There are two vectors: one for a receiver interrupt and one for a transmitter interrupt. The interrupt
logic uses VECRQSTB H to indicate which vector is enabled.
The LSI-II's interrupt acknowledge signal (BIAKI L/BIAKO L) is daisy-chained through the devices
on the LSI-II bus. A device's priority is established by its position in the interrupt acknowledge daisychain. The interrupt acknowledge chain goes through both the receiver section and the transmitter
section of the module's interrupt logic. It goes through the receiver section first, thereby giving the
receiver channel priority over the transmitter channel.
A receiver interrupt is initiated when the RBUF has received and assembled a character of data and is
ready to transfer it to the computer. A transmitter interrupt is initiated when the XBUF's holding
register is empty and is ready for another data input from the computer.
The DLVll-E differs from the DLVII-F in that it recognizes a second condition requiring a receiver
interrupt. The DLVII-E initiates a receiver interrupt when the data set that it is interfacing signals for
a handshake. The computer program can read the DLVll-E's RCSR to determine whether the
receiver interrupt is for a handshake or for another character of data.

2-7

2.3.8 Baud Rate Control
The baud rate control circuit generates clock signals that control the speeds at which the RBUF and
XBUF move serial data. The circuit can provide a common clock to both data buffer circuits (common
speed operation) or separate transmit and receive clocks (split speed operation).
In common speed operation, both transmit and receive baud rates are either set by wire wrap jumpers
RO through R3 or programmable by three-state bus lines DAT12 H through DAT15 H. In split speed
operation, the transmit baud rate is set by jumpers TO through T3, while the receive baud rate remains
under the control of either RO through R3 or the computer program.
Should it be desired to use a baud rate not available from the baud rate control's crystal-controlled
clock generator, the module has provisions for external inputs for both the transmit and receive clocks.
2.3.9 Break Logic
A BREAK signal is a continuous spacing condition on the serial data line. The DLVll-E and
DLV11-F can receive BREAK signals from a peripheral device (normally the console device) and can
transmit BREAK signals to a peripheral device (normally another processor). Either operation can be
enabled or inhibited by wire wrap jumpers.
When the interface module receives a BREAK signal from the serial data line, it interprets the absence
of STOP bits as a framing error. It can respond to this apparent error (or to an actual error) in one of
three ways:
1.

2.
3.

It can ignore it the apparent error.
It can place the LSI-ll in the HALT mode.
It can cause the LSI-II to re-boot.

Which action the module takes is controlled by wire wrap jumpers. To place the computer in the
HALT mode, the break logic asserts BHALT L. To cause the computer to reload a bootstrap, the
break logic negates BDCOK H. Refer to Paragraph 5.9 for further information.
2.3.10 Maintenance Mode Logic
The DLVII-E and DLVll-F have a maintenance mode for verifying the operation of the modules'
data paths up to (but not including) the peripheral interface circuitry. This mode is controlled by the
computer program, but is used only for checking the interface module, not the computer. In maintenance mode, data from the computer is transferred from the bus interface to the XBUF and serialized,
as in normal operation. But then, in addition to going to the peripheral interface circuit, a sample of
the XBUF's serial output is also routed back to the RBUF's serial input. There it is converted to
parallel, placed on the three-state bus to the bus interface, and transferred back into the computer. The
program can then compare the received data with the transmitted data to check for errors.
2.3.11 DLV11-E Peripheral Interface
The peripheral interface circuitry converts the DLVII-E's data and modem control signals from TTL
levels to EIA-standard bipolar levels for the peripheral device. Likewise, it converts the peripheral's
data and control lines from EIA levels to TTL levels for the interface module.
The circuit can receive four modem control signals (RING, CARRIER, CLEAR TO SEND, and
SECONDARY RECEIVED DATA) and can transmit four modem control signals (DATA TERMINAL READY, REQUEST TO SEND, FORCE BUSY, and SECONDARY TRANSMITTED
DATA). The control signals are routed through the control/status registers. The interrupt logic uses
the received control signals to initiate data set interrupts. The program uses the transmitted control
signals to perform handshakes with the data set. Refer to Paragraph 5.11 for an example of a handshake sequence.

2-8

2.3.12 DLVll-F Peripheral Interface
The DLVII-F peripheral interface operates in one of two possible modes:
1.

EIA Data Leads Only - This type of operation supports terminals that use EIA levels, but
do not require control signal interaction.

20 rnA Current Loop - This operation supports terminals that use either active or passive
current loops. It also controls the paper tape reader on DIGITAL-modified TTY units that
have a reader run relay.

When interfacing EIA-Ievel equipment, the module performs the TTL-to-EIA and EIA-to-TTL level
conversion on the transmit and receive data leads only. During data leads only operation, the module
does not monitor incoming control signals. Outgoing control signals (REQUEST TO SEND, FORCE
BUSY, and DATA TERMINAL READY) are held by driver circuits in a continuous TRUE
condition.
When the DLVII-F interfaces a 20 rnA current loop peripheral device, it can bejumpered to operate in
either active or passive configuration. In the active configuration, the peripheral interface supplies the
current for the loop; in the passive configuration, the current is supplied by the peripheral device. In
either case, the receive data line from the peripheral is optically isolated from the DLVI1-F's internal
data path.
The 20 rnA current loop transmitter operates in either the active or passive configuration. The transmit
data lines are optically isolated from the DLVII-F's internal data path only in the passive
configuration.
A Reader Run signal is produced for a peripheral device that has a reader run relay. When enabled by
the program, the peripheral interface circuit supplies current to the relay, causing the reader to
advance the paper tape.

2.3.13 DC-to-DC Power Inverter
Both the DLVII-E and DLVI1-F need -12 V for the data buffers and the peripheral interface. This
voltage is produced on the module by a small power inverter. The inverter uses the + 12 V power
available on the LSI-II backplane to produce a regulated -12 V for the data buffers and peripheral
interface circuits.

2-9

CHAPTER 3
INSTALLATION

3.1 GENERAL
This chapter describes the jumper configuration, the installation requirements, and the checkout of the
DLVll-E and DLVll-F asynchronous line interface modules. The wire wrap jumper functions are
defined and application examples are presented. Wire wrapping instructions are presented in
Appendix B.
3.2 CONFIGURATION
Before installing the module, ensure that it is configured for your application. The jumper locations
are depicted in Figures 3-1 and 3-2. Their functions are defined in Tables 3-1, 3-2, and 3-3. Table 3-4
explains the configuration in which the modules are shipped from the factory. Table 3-5 lists common
applications of the DLVll-E and DLV11-F; Figures 3-3 and 3-4 illustrate examples of typical cabling
requirements.
The DLVll-F is shipped from the factory with capacitor C29 installed (Figure 3-2). This capacitor is
provided for applications using Teletype® terminals. For applications using DIGITAL terminals, remove capacitor C29.

3.3 MODULE INSTALLATION
The DLVll-E or DLVll-F module can be installed in any slots in the LSI-ll backplane, except the
first four slots (the LSI-ll processor always occupies the first slots). Do not leave any unused option
locations between the processor and the DLVll-E or DLV11-F. An open slot would break the interrupt acknowledge daisy chain. The priority of the module is determined by its proximity to the processor on the bus (refer to Figure 3-5). The closer the slot is to the processor module, the higher the
interface module's priority.
Determine the appropriate slot for the module. For example, if a DLVll-E is interfacing communications lines from a host computer, it would normally be placed in the slot closest to the processor
module, followed by the module interfacing the console terminal. Refer to Microcomputer Handbook
(DIGITAL part number EB 06583 76) for system considerations.

®Teletype is a registered trademark of Teletype Corporation.

3-1

-Foll-FR
C1

-M1

---PB

ifni! l~'---___---'
II

I" IIIII

y-B
H

11-5172

Figure 3-1

DLV11-E Jumper Locations

3-2

["
II II

IIIII

;a~ ilI~

M~!!:~

~ liiiilili
QC29
Qp"NM

a: a: a: a:

IIII

M"ItIIHC"",,CO

»»»

III111

11-5173

Figure 3-2

DLVII-F Jumper Locations

3-3

Table 3-1

Jumper Definitions

NOTE
This table pertains to both the DLVll-E and the
DLVll-F, except as noted. Jumpers are inserted to
enable the function they control except for those
jumpers that indicate negation (such as "-B" and
"B"). Negated jumpers are removed to enable the
functions they control.
Jumper

Function

A3-AI2

These jumpers correspond to bits 3-12 of the address word. When
inserted, they will cause the bus interface to check for a True condition
on the corresponding address bit.

V3-V8

Used to generate the vector during an interrupt transaction. Each
inserted jumper will assert the corresponding vector address bit on the
LSI-II bus.

RO-R3

Receiver and transmitter baud rate select jumpers, during common
speed operation.
Receiver only baud rate select jumpers during split speed operation (see
Table 3-2).

TO-T3

Transmitter baud rate select jumpers during split speed operation.
Both receiver and transmitter baud rate if maintenance mode is entered
during split speed operation (see Tale 3-2).

Jumper is inserted to enable Break generation.

Jumper is inserted for operation with parity.

Removed for even parity; inserted for odd parity. Receiver checks for
appropriate parity and transmitter inserts appropriate parity.

I, 2

These jumpers select the desired number of data bits (see Table 3-3).

Jumper is inserted to enable the programmable baud rate capability.

C,CI

These jumpers are inserted for common speed operation. (Note that S
and Sl must be removed when C and Cl are inserted.)

S, SI

Inserted for split speed operation. (Note that C and Cl must be removed when Sand SI are inserted.)

This jumper is inserted to assert BHALT L when a framing error is
received, except when the Maintenance bit is set. This places the LSI-II
in the halt mode.

3-4

Table 3-1

Jumper Definitions (Cont)

Jumper

Function

B, -B
(DLVII-E)

Jumper B is inserted to negate BDCOK H when a BREAK signal or
framing error is received, except when the Maintenance bit is set. This
causes the LSI-II to reload the bootstrap. (Jumper -B orB must be
removed when B is inserted.)

B,lf
(DLVII-F)
-FD
(DLVII-E
only)

Jumper is removed to force DATA TERMINAL READY signal on.

-FR
(DLVII-E
only)

Jumper is removed to force REQUEST TO SEND signal on.

RS
(DLVII-E
only)

This jumper is inserted to enable normal transmission of the
REQUEST TO SEND signal.

FB
(DLVII-E
only)

Inserted to enable transmission of the FORCE BUSY signal (for Bell
model 103E data sets).

IA,2A,
and 3A
(DLVII-F
only)

These three jumpers are inserted to make the 20 rnA current loop
receiver active. (Jumpers IP and 2P must be removed when lA, 2A, and
3A are inserted.)

IP, 2P
(DLVII-F
only)

These jumpers are inserted to make the 20 rnA current loop receiver
passive. (Jumpers lA, 2A, and 3A must be removed when I P and 2P are
install ed. )

4A,5A
(DLVII-F
only)

Inserted to make the 20 rnA current loop transmitter active. (Jumpers
3P and 4P must be removed when 4A and 5A are inserted.)

3P, 4P
(DLVII-F
only)

Inserted to make the 20 rnA current loop transmitter passive. (Jumpers
4A and 5A must be removed when 3P and 4P are inserted.)

Jumper is removed to enable the error flags to be read in the high byte
of the Receiver Buffer.

(DLVII-F
only)
MT
(DLVII-F
only)

When inserted, enables maintenance bit.

M,MI

These are test jumpers used during the manufacture of the module.
They are not defined for field use.

3-5

Table 3-2 Baud Rate Selections

Program Control
Receive Jumpers
Transmit Jumpers

Bit

15
R3
T3

14
R2
T2

13
Rl
Tl

12
RO
TO

11*

I
I
I
I
I
I
I
I

I
I
I
I

I
I

R
R

R
R
R
R

I
I

R
R

R
R
R
R
R
R
R

I
I
I
I

I
I

R
R

R
R
R

I
I

R
R
R
R
R
R
R

Baud
Rate
50
75
110
134.5
150
300
600
1200
1800
2000
2400
3600
4800
7200
9600

I = Jumper Inserted = Program Bit Cleared.
R = Jumper Removed = Program Bit Set.
*Bit 11 of the XCSR (Write Only Bit) must be set in order to select a new baud rate under program control. Also,
jumper PB must be inserted to enable baud rate selection under program control.

Table 3-3 Data Bit Selections
Jumpers
2
1

Number of Data Bits

I
R

R
I

5
6
7
8

3-6

Table 3-4 Jumper Configuration When Shipped

Jumper
Designation
A3
A4
A5
A6
A7
A8
A9
AIO
All
Al2

Jumper State
DLVII-E DLVll-F
R

I
I
I

R
R
R

R
R

Jumpers A3 through Al2 implement device address
1756lX for the DLVII-E and 17756X for the DLVII-F.
The least significant octal digit is hardwired on the module
to address the four device registers as follows:

R
R
R
R
R

V3
V4
V5
V6
V7
V8

I
I
I

R
R

I
I
I

RO
RI
R2
R3

Function Implemented

R
R

X=O
X=2
X=4
X=6

RCSR
RBUF
XCSR
XBUF

This jumper selection implements interrupt vector address
300 s for receiver interrupts and 304 s for transmitter
interrupts on the DLVII-E. On the DLVll-F it selects
60 s for receiver interrupts and 64 s for transmitter
interrupts.

I
R

I
I

R
R
R

Break generation is enabled.
Parity bit is disabled.

Parity type is not applicable when P is removed.

R
R

Operation with 8 data bits per character.

2
PB

Programmable baud rate Junction disabled.

C
Cl

I
I

Common speed operation enabled.

T2
T3
BG
P

The module is configured to receive at 110 baud.

The transmitter is configured for 9600 baud if split speed
operation is used.

3-7

Table 3-4 Jumper Configuration WhenShipped (Cont)

Jumper
Designation

Jumper State
DLVll-E ; DLVII-F

Function Implemented

S
Sl

R
R

Split speed operation disabled.

Halt on framing error disabled on DLVII-E;enabled
on DLVll-F.

B
-B

R
I

R
N/A

N/A

-FD

N/A

-FR

N/A

The circuitry controlling the REQUEST TO SEND signal
is enabled.

N/A

The FORCE BUSY signal is disabled.

lA
2A
3A
lP
2P

N/A
N/A
N/A
N/A
N/A

4A
5A
3P
4P

N/A
N/A
N/A
N/A

I
I

-EF

N/A

Error flags are enabled on DLVI1-E; disabled on DLVII-F.

M
Ml

R
R

Factory test jumpers. Not defined for field use.

N/A

Maintenance bit disabled.

Boot on framing error disabled.

The DATA TERMINAL READY signal is not forced
continuously True.
The REQUEST TO SEND signal is not forced continuously
True.

The 20 rnA current loop receiver is configured as an
active receiver.

R
R
The 20 rnA current loop transmitter is configured for
active operation.

R
R

3-8

Table 3-5

Module Application Examples

Module/Mode

Equipment Supported

DLVII-E
Modem Control

Bell Data Sets, Models:
103
202C
202D
212A

DLVII-F
EIA Data Leads Only
DLVII-F
20 rnA Current Loop

Bell Model 103 Data Set (in automode).
Teletype Model 37 Teletypewriter
Teletype Model 33 and 35 Teletypewriters
DIGITAL equipment:
LA36 DECwriter (read/write)
LA35 DECwriter (read only)
VT05B Alphanumeric Terminal
VT50 DECscope (l2Iine)
VT52 DECscope (24 line)
RT02 Alphanumeric Terminals
DFOI-A Acoustic Telephone Coupler
LT33 Teletypewriter
LT35 Teletypewriter

DATA SET CONTROL
40 PIN
CONN
OLV11-E

OB-25

~~________________B_CO_5_C__________________

DATASET
BELL 103
BELL 202

11- 4961

Figure 3-3

DLVII-E Cabling Example

3-9

CURRENT LOOP MODE
40 PIN
CONN.
DLVII -F

DLV"-F
( RECEIVER
PASS IVE,
TRANSMITTER
ACTIVEl

DLV11-F
( RECEIVER
PASSIVE,
TRANSMITTER
PASSIVEl

r:l

MATE-NLOK

r:l

BC05M

LJI-----------1LJ

40 PIN
CONN.

tJ
40 PIN
CONN.

M Lt--------------i

MATE-NLOK
BC05M

MATE-NLOK
BC05F

MATE-NLOK

tJt--_B_C_0_5M
_ _8

GtJ

40 PIN
CONN.
BC05M

MATE-NLOK

GI--_BC_0_5_F---IG

LA36
VT52
TTY

DLV11-F
( RECEIVER
PASSIVE,
TRANSMITTER
ACTIVE)

40 PIN
CONN.

8 t - -_ _B_C_0_5_M____t J

DLII-C

ErA" DATA LEADS ONLY" MODE
40 PIN
CONN
DLV11 -F

DB-25

[:]~_ _ _B_C_0_5C_ _ _~[:]

BC03P

EIA/CCITT
TERMINAL
VT06

NULL MODEM CABLE

40 PIN
CONN
DLV"-F

DB -25

[:]~_ _ _ _ _ _ _ _ _ _B_C_0_5_C_ _ _ _ _ _ _ _ _ _ _[ : ]

MODEL 103
DATASET
(AUTO MODEl

,,- 4962

Figure 3-4

DLVII-F Cabling Examples

3-10

VI EW FROM MODULE SIDE OF BACKPLANE

B
KDll-F

MSVl1 - B

DLVl1- E

MSVl1- B

RXVl1

REVl1

DRVl1

CONNECTOR
BLOCK
11-4963

Figure 3-5

Typical Backplane Configuration

After the module has been configured properly and the desired location determined, install it in the
computer as follows:
CAUTION
DC power must be removed from the backplane during module insertion and removal.
The module and backplane connector block may be
damaged if the module is plugged in backwards.
1.

Position the module so that the components side is facing row 1.

Slide the module into its slot, taking care that the module fingers mesh correctly with the
backplane connector block.

Press the module into the connector block, making sure that the deep notch on the module
seats against the connector block rib.

Next, plug the interface cable into the module's 40-pin header connector.

When the other end of the interface cable is installed, the module can be powered up and checked out.
Interface cable installations are shown in Figures 3-3 and 3-4. Interface connector pinning is listed in
Tables 3-6 and 3-7. Bus connector pinning is listed in Table 3-8.
3.4 MODULE CHECKOUT
A diagnostic program is shipped with the module, and should be run to verify the proper operation of
the module. The program runs on an LSI-ll with the most basic options. Perform the diagnostic
checkout as explained in Paragraph 3.4.1 or 3.4.2. If a malfunction is detected, contact the nearest
DIGITAL Field Service office.

3-11

Table 3-6
Header
Berg
Pin
A
B
C
D
E
F

DLVll-E 40-Pin Header Connector Pinning
M8017 Module
Signal Names

BC05C Modem Cable
Signal Names

Ground
Ground
Force Busy (EIA)
Serial Input (TTL)
Serial Output (EIA)

Ground
Ground
Force Busy
Sec. Clear to Send
*
Interlock In 5
Transmitted Data

Serial Input (EIA)

Received Data

H
J

K
L
M
N
P
R
S
T

External Clock
Interlock Out Serial Clock XMIT
Sec Request to Send
Serial Clock R CVR

EIA Interlock

Clear to Send (EIA)

Clear to Send

Request to Send (EIA)

Request to Send
- Power
Ring
+ Power
Data Set Ready

U
V
W
X
Y
Z
AA
BB
CC
DD
EE
FF

HH
11

Ring (EIA)

Carrier (EIA)
External Clock Input (TTL)
Data Terminal RDY (EIA)

Carrier

Secondary XMIT (EIA)
External Clock ENB (TTL)
Secondary Rec (EIA)

202 Sec XMIT

Data Terminal RDY

202 Sec RCVR

KK
LL
MM
NN
PP
RR
SS
TT

UU
VV

EIA SecXMIT
Signal Quality
EIA Sec RCVR
Serial Output (TTL)
+5V
Ground
Ground

*This jumper is built into the cable.

3-12

Ground
Ground

Table 3-7

DLVll-F 4O-Pin Header Connector Pinning

Header
Pin

M8028 Module
Signal Names

BCOSC Modem Cable
Signal Names

A
B
C
D
E

Ground
Ground
Force Busy (EIA)

Ground
Ground
Force Busy
Sec Clear to Send
Interlock In ~ --*Transmitted Data

H
J

K
L
M

Serial Input (TTL)
Serial Output (EIA)
20 rnA Interlock
Serial Input (EIA)
Serial Input + (20 rnA)
EIA Interlock

N
P
R
S
T
U
V
W

EE
FF

Request to Send (EIA)

Received Data +
External Clock
Interlock Out
Serial Clock XMIT
Sec Request to Send
Serial Clock RCVR

Received Data Request to Send
- Power
Ring
+ Power
Data Set Ready
Transmitted Data +
Carrier

Ext. Clock Input (TTL)
Data Terminal RDY
(EIA)
Reader Run - (20 rnA)

Data Terminal RDY
Reader Run202 SecXMIT

Ext. Clock Enb (TTL)
202 Sec RCVR
Serial Output
EIASecXMIT
Signal Quality
EIA Sec RCVR

Interlock Out

Serial Output+(20 rnA)

LL
MM
PP
RR
SS
TT

Interlock In ~ *

Clear to Send

Ground

Received Data

Serial Input - (20 rnA)

X
Y
Z
AA
BB
CC
DD

BCOSM 20 mA Cable

Reader Run+(20 rnA)

Reader Run+
Signal Rate

Serial Output (TTL)
+5V
Ground
Ground

Ground
Ground

3-13

Ground
Ground

Table 3-8DLVll-E and DLVll-F Edge Connector Pinning

~ ~ ",

Mnemonic.

AA2
BA2
AD2
AP2
AU2
AV2
BE2
BF2
BH2
BJ2
BK2
BL2
BM2
BN2
BP2
BR2
BS2
BT2
BU2
BV2
AH2
AE2
API
AM2
AN2
AT2
AR2
AS2
AL2
AF2
AJ2
BA1
AC2
AT1
BC2
BTl
AK1~
ALI
BK1'!J
BL1
BC1
BD1
BEl
BF1
BH1

;

:' (,:"

+12
BBS7L
BDALOL
BDAL1L
BDAL2L
BDAL3L
BDAL4L
,BDAL5 L
BDAL6L
BDAL7L'
BDAL8L
BDAL9L
BDAL lOL
BDAL 11 L
BDAL 12L
BDAL13L
BDAL14L
BDAL 15 L
BDINL
BDOUTL
BHALTL
BIAK I L*
BIAK 0 L*
BINIT L
BDMGIL*
BDMGOL*
BIRQL
BRPLYL
BSYNCL
BDCOKH
GND
GND(
GND
GND
MSPARE A (-12 V)
MSPARE B (EXT R CLK)
SSPARE4
SSPARE5
SSPARE6
SSPARE7
SSPARE 8 (EXT T CLK)

*These signals are not bussed, they are daisy-chained.
uThis jumper is wired on the backplane.

3-14

**
**

3.4.1 DLVll-E Checkout
To verify the operation of the DLVII-E, turn off the dc power and remove the interface cable from the
data set. Leave the other end connected to the module's header connector. Plug an H315 terminator
into the free end of the interface cable. Power up the computer. Load and start MAINDEC-llDVDV A. When the program has been completed successfully, turn off the dc power and reconnect the
interface cable to the data set.
3.4.2 DLVll-F Checkout
The DLVI1-F does not require a terminator plug for checkout. Load and start MAINDEC-llDVDVC. Successful completion of the program indicates the module is acceptable.

3-15

CHAPTER 4
PROGRAMMING

4.1 INTRODUCTION
Both the DLVII-E and DLVII-F are program compatible with PDP-ll software. Programs written
for PDP-II's using DLlI-A through -D interface modules will run on an LSI-ll using a DLVll-F
configured for the same application. Programs written for a DLlI-E will run with a DLVII-E. Also,
the D LVII-F will operate with LSI-ll programs written for the DLVII.
This chapter defines the bits in each of the four device registers, discusses interrupts and timing considerations, and gives programming examples.

4.2 DEVICE REGISTERS
All software control of the DLVII-E or DLVII-F Asynchronous Line Interface is performed by
means of four device registers. These registers have been assigned bus addresses and can be read or
loaded (with the exceptions noted) using any LSI-II instruction referring to their addresses. Address
assignments can be changed by altering jumpers on the module to correspond to any address within
the range of 160000 to 177777. Table 4-1 lists the addresses of the registers when the module is used to
interface a console device. The RCSR is at the base address. Each subsequent register is two locations
up from the one preceding it.
Table 4-1

Mnemonic

Address

Receiver Control/Status Register
Receiver Buffer Register
Transmitter Control/Status Register
Transmitter Buffer Register

RCSR
RBUF
XCSR
XBUF

177560
177562
177564
177566

The DLVII-E RCSR differs from the DLVII-F RCSR; therefore, the bits for these two RCSRs are
defined separately. The DLVll-E and DLVll-F operate identically with respect to the three other
device registers. The bit definition for these registers applies to both modules. Figures 4-1 and 4-2 show
RCSR bit assignments. Figures 4-3, 4-4, and 4-5 show the RBUF, XCSR, and XBUF, respectively.
Tables 4-2 through 4-6 define the bit assignments.

4-1

,,- 4964

Figure 4-1

DLVII-E RCSR Bit Assignments

Table 4-2

DLVll-E RCSR Bit Assignments

Bit

Name

Meaning and Operation

DATA SETINT
(Data Set Interrupt)

This bit initiates an interrupt sequence provided
the DATA SET INT ENB bit (05) is also set.
This bit is set whenever CAR DET, CLR TO
SEND, or SEC REC changes state; i.e., on a O-to-l
or I-to-O transition of anyone of these bits. It is
also set when RING changes from 0 to 1.
Cleared by INIT or by reading the RCSR. Because
reading the register clears the bit, it is, in effect, a
"read-once" bit.

RING

When set, indicates that a RINGING signal is
being received from the dataset. Note that the
RINGING signal is not a level but an EIA control
with the cycle time as shown below:

2 sec

_4_se_c_---I1 2 sec 14 sec

L..I

2 sec

Read-only bit.
13

CLRTOSEND
(Clear to Send)

The state of this bit is dependent on the state of the
CLEAR TO SEND signal from the data set. When
set, this bit indicates an ON condition; when clear,
it indicates an OFF condition.
Read-only bit.

CARDET
(Carrier Detect)

This bit is set when the data carrier is received.
When clear, it indicates either the end of the current transmission activity or an error condition.
Read-only bit.

RCVRACT
(Receiver Active)

When set, this bit indicates that the DLVII-E's receiver is active. The bit is set at the center of the
ST ART bit, which is the beginning of the input serial data from the device, and is cleared by the leading edge of R DONE H.
Read-only bit; cleared by INIT or by R DONE H
(bit 07)

4-2

Table 4-2

DLVll-E RCSR Bit Assignments (Cont)

Bit

Name

Meaning and Operation

SECREC
(Secondary Received
or Supervisory
Received Data)

This bit provides a receive capability for the reverse
channel of a remote station. A space (~+ 10. V) is
read as a 1. (A transmit capability is provided by
bit 03.)
Read-only bit.

9-8

Not Used

Reserved for future use.

RCVRDONE
(Receiver Done)

This bit is set when an entire character has been
received and is ready for transfer to the LSI -Il.
When set, initiates an interrupt sequence provided
RCVR INT ENB (bit 06) is also set.
Cleared whenever the receiver buffer (RBUF) is
addressed. Also cleared by INIT.
Read-only bit

RCVRINTENB
(Receiver Interrupt
Enable)

When set, allows an interrupt sequence to start
when RCVR DONE (bit 07) sets.
Read/write bit; cleared by INIT. See Note 1.

DSETINTENB
(Data Set Interrupt
Enable)

When set, allows an inerrupt sequence to start
when DATA SET INT (bit 15) sets.
Read/write bit; cleared by INIT. See Note 1.

Not Used

Reserved for future use.

SECXMIT
(Secondary Transmitted
or Supervisory
Transmitted Data)

This bit provides a transmit capability for a reverse
channel of a remote station. When set, transmits a
space (~+ 10 V). (A receive capability is provided
by bit 10.)
Read/write bit; cleared by INIT.

REQTOSEND
(Request to Send)

A control lead to the data set which is required for
transmission. A jumper on the DLVII-E ties this
bit to REQ TO SEND or FORCE BUSY in the
data set.
Read/write bit; cleared by INIT.

4-3

Table 4-2

DLVll-E RCSR Bit Assignments (Cont)

Bit

Name

Meaning and Operation

DTR (Data Terminal)
Ready)

A control lead for the data set communication
channel. When set, permits connection to the channel. When clear, disconnects the interface from the
channel.
Read/write bit; must be cleared by the program, is
not cleared by INIT. (See Note 2.)

NOTES
When clearing an interrupt enable bit,
first set the processor to its highest priority [Processor Status Word (PSW) bit 7
= 1]. After the interrupt enable bit is
cleared, the processor may be returned to
its normal priority (pSW bit 7 = 0).
For example:
MTPS #200
BIC #100, CSR
MTPS #0
EXIT
For further information refer to Paragraph 4.6.

The state of this bit is not defined after
power-up.

4-4

,,- 4965

Figure 4-2

DLVII-F RCSR Bit Assignments

Table 4·3 DLVll·F RCSR Bit Assignments
Bit

Name

Meaning and Operation

15-12

Not Used

Reserved for future use.

RCVRACT
Receiver
Active)

When set, this bit indicates that the DLVII-F interface receiver is active. The bit is set at the center
of the START bit, which is the beginning of the
input serial data from the device, and is cleared by
the leading edge of RDONE H.
Read-only bit; cleared by INIT or by RCVR
DONE (bit 07).

10-08

Not Used

Reserved for future use.

RCVRDONE
(Receiver
Done)

This bit is set when an entire character has been
received and is ready for transfer to the LSI-II bus.
When set, initiates an interrupt sequence provided
RCVR INT ENB (bit 06) is also set.
Read-only bit; cleared whenever the receiver buffer
(RBUF) is addressed or whenever RDR ENB
(bit 00) is set. Also cleared by IN IT .

RCVRINT
ENB
(Receiver
Interrupt
Enable)

When set, allows an interrupt sequence to start
when RCVR DONE (bit 07) sets.

05-01

Not Used

Reserved for future use.

RDRENB
(Reader
Enable)

When set, this bit advances the paper-tape reader
in DIGITAL-modified TTY units (LT33-C; LT35A, -C) and clears the RCVR DONE bit (bit 07).

Read/write bit; cleared by INIT.

This bit is cleared at the middle of the START bit, .
which is the beginning of the serial input from an
external device. Also cleared by INIT.
Write-only bit.

4-5

RESERVED

RECEIVED DATA BITS

,,- 4966

Figure 4-3

DLVII-E and DLVll-F RBUF Bit Assignments

Table 4-4

DLVll-E and DLVll-F RBUF Bit Assignments

Bit

Name

Meaning and Operation

ERROR
(Error)

Used to indicate that an error condition is present.
This bit is the logical OR of OR ERR, FR ERR,
and P ERR (bits 14, 13, and 12, respectively).
Whenever one of these bits is set, it causes ERROR
to set. This bit is not connected to the interrupt
logic.
Read-only bit; cleared by removing the error-producing condition.
NOTE
Error indications remain present until the next character is received, at which time the error bits are
updated. IN IT clears the error bits.

OR ERR
(Overrun
Error)

When set, indicates that reading of the previously
received character was not completed (RCVR
DONE not cleared) prior to receiving a new
character.
Read-only bit. Cleared by INIT.

FRERR
(Framing
Error)

When set, indicates that the character that was
read had no valid STOP bit.
Read-only bit. Cleared by INIT.

PERR
(Parity
Error)

When set, indicates that the parity received does
. not agree with the expected parity. This bit is
always 0 if no parity is selected.
Read-only bit. Cleared by INIT.

11-08

Not Used

Reserved for future use.

07-00

RECEIVED
DATA BITS

Holds the character just read. If less than eight bits
are selected, then the buffer is right-justified into
the least significant bit positions. In this case, the
higher unused bit or bits are read as O's.
Read-only bits; not cleared by INIT.
4-6

RESERVED

11-4967

Figure 4-4

OLVII-E and OLVll-F XCSR Bit Assignments

Table 4-5

DLVll-E and DLVll-F XCSR Bit Assignments

Bit

Name

Meaning and Operation

15-12

PBR SEL
(Programmable
Baud Rate
Select)

When set, these bits choose a baud rate from
50-9600 baud. See Table 3-2.
Write-only bits.

PBRENB
(Programmable
Baud Rate
Enable)

This bit must be set in order to select a new baud
rate indicated by bits 12 to 15.

1~08

Not Used

Reserved for future use.

XMITROY
(Transmitter
Ready)

This bit is set when the transmitter buffer (XBUF)
can accept another character. When set, it initiates
an interrupt sequence provided XMIT INT END
(Bit 06) is also set.

Write-only bits.

Read-only bit; set by INIT.
XMITINTENB
(Transmitter
Interrupt
Enable)

When set, allows an interrupt sequence to start
when XMIT ROY (bit 07) is set.

05':"03

Not Used

Reserved for future use.

MAINT

Used for maintenance function. When set, connects the transmitter serial output to the receiver
serial input while disconnecting the external device
from the receiver serial input. It also forces the receiver to run at transmitter baud rate speed when
split speed operation is enabled.

Read/write bits; cleared by INIT. See Note.

Read/write bit; cleared by IN IT

4-7

Table 4-5 DLVll-E and DLVll-F XCSR Bit Assignments (Cont)
Bit

Name

Meaning and Operation

Not Used

Reserved for future use.

BREAK

When set, transmits a continuous space to the external device.
Read/write bit; cleared by INIT.
NOTE
When clearing an interrupt enable bit, first set the
processor to its highest priority (PSW bit 7 = 1).
After the interrupt enable bit is cleared, the processor may be returned to its normal priority (PSW bit
7 = 0). For example:
MTPS #200
BIC #100, CSR
MTPS #0
EXIT
For further information refer to Paragraph 4.6.

00
TRANSMITTER DATA BUFFER

RESERVED

11-5155

Figure4-5

DLVI1-E and DLVII-F XBUF Bit Assignments

Table 4-6 DLVll-E and DLVll-F XBUF Bit Assignments
Bit

Name

Meaning and Operation

15-08

Not Used

Not defined. Not necessarily read as Os.

07-00

TRANSMITTER
DATA BUFFER

Holds the character to be transferred to the external device. If less than eight bits are used, the character must be loaded so that it is right-justified into
the least significant bits.
Write-only bits. Not necessarily read as Os.

4-8

The unused and load-only bits are always read as O's except for the XBUF, in which unused bits are
undefined. Loading unused or read-only bits has no effect on the bit position. The mnemonic INIT
refers to the initialization signal issued by the processor. Initialization is caused by one of the following: issuing a programmed RESET instruction; pressing "G" while in ODT; or the occurrence of a
power-up or power-down condition of the processor power supply.
In the following descriptions, "transmitter" refers to those registers and bits involved in accepting a
parallel character from the LSI-II for serial transmission to the external device; "receiver" refers to
those registers and bits involved with receiving serial information from the external device for parallel
transfer to the LSI-II.
4.3 INTERRUPTS
Both the DLVII-E and the DLVII-F have two interrupt channels: one for receiver interrupts and one
for transmitter interrupts. These two channels operate independently. If, however, simultaneous interrupt requests occur, the receiver channel has priority over the transmitter channel.
In both the DLVI1-E and the DLVII-F, a transmitter interrupt can occur only if the interrupt enable
bit (XMIT INT ENB) in the XCSR is set. With XMIT INT ENB set, setting the transmitter ready
(XMIT RDY) bit initiates an interrupt request. When XMIT RDY is set, it indicates that the XBUF is
empty and ready to accept another character from the bus for transfer to the external device.
A receiver data interrupt can occur only if the interrupt enable (RCVR INT ENB) bit in the receiver
RCSR is set. With RCVR INT ENB set, setting the receiver done (RCVR DONE) bit initiates an
interrupt request. When RCVR DONE is set, it indicates that an entire character has been received
and is ready for transfer to the bus. The receiver data interrupt occurs in both the DLVll-E and the
DLVII-F. The DLVI1-E also has a data set interrupt.
The receiver portion of the DLVII-E handles multisource interrupts. One of the receiver interrupt
circuits is activated by RCVR INT ENB and RCVR DONE. The other interrupt circuit can cause an
interrupt only if the data set interrupt enable bit (DATA SET INT ENB) in the RCSR is set. With
DATA SET INT ENB set, setting the DATA SET INT bit initiates an interrupt request. The DATA
SET INT bit can be set by any of four other bits: CAR DET, CLR TO SEND, SEC REC, or RING.
NOTE
When servicing a receiver interrupt from the
DLVll-E, if a second receiver interrupt condition
develops a second interrupt request may not occur.
To avoid missing this second interrupt condition,
either all possible receiver interrupt conditions
should be checked after servicing the first condition,
or else both interrupt enable bits (bits 05 and 06)
should be cleared upon entry to the service routine
and then set at the end of service.

4-9

4.4 TIMING CONSIDERATIONS;
,
,
'
When pro.gra~mingthe DLVII-E or,DLVll-F Asynchronous Line Interface, it is important to consider timing of certain functions in order to use the system in the most efficient manner. Timing
considerations for the receiver, transmitter, and break generation logic are discussed in the following
par~graphs.
"
4.4.1 Receiver
The RCVR ,DONE flag (bit 07 in the RCSR) sets when the receiver has assembled a full character.
This occur~ at the middle of the first STOP bit.·Because the receiver is dOllble buffered, data remains
valid until the next character is received and assembled. This permits one full character time for
servicing the receiver interrupt..
4.4.2 Transmitter
The transmitter. is also double buffered. The XMIT RDY flag (bit 07 in the XCSR) is set after initialization. When the XBUF is loaded with the first character from the bus, the flag clears but then
sets again within a function of a bit time. A second character can then be loaded, which clears the flag
again. The. flag. then remains cleared for nearly one full . character time.
.,

4.4.3 BREA~ Gener"ation Logic
,
When the BREAK bit (bit 00 in the XCSR) is set, it causes transmission of a continuous space.
Because the XMIT RDY flag continues to function normally, the duration of a BREAK can be timed
by the pseudo-tran~mission of a number of characters. However,because the transmitter is double
buffered, a null character (all O's) should precede transmission of the BREAK to ensure that the
previous character clears .the line. In a similar manner, the final pseudo-transmitted character in the
BREAK should be null.
4.4.4 System Reset Timing
A system reset should not be performed immediately after the processor loads a character into the
transmitter buffer for serial transmission. If the system is reset. before the last character has left the
transmitter buffer, the character will be lost when the buffer is cleared by INIT. To avoid this, the
program should transmit two m,lll characters after the last character, and then wait for XMIT RDY to
return to its true state.
'
NOTE
Programs developed on the DLV-U Serial Line Unit
(M7940) may not inclpde these null characters, since
theDLV-Us transmitter buffer is nQt cleared by the
I~IT signal.
'
4.5 PROGRAMMING EXAMPLES '
Table 4-7 is an example of a typical program that can be used as an echo program for a DLVll-E
interfacing a Bell Model 103 data set. When a remote terminal dials in, this program answers the call
and provides a character-by-character echo. Characters are also copied onto the console device.
Figure 4-6 depicts a DLVII-F program. The program demonstrates the flexibility of programming
with interrupts. It is performed on a console terminal interfaced by the DLVll-F. The program exercises the module's full-duplex capability.

4-10

Table 4-7 DLVll-E Programming Example

000200

000200
000167

001616

START·

.=200
IMP

BEGIN

;JUMP TO BEGINNING
;OFPROGRAM

:SYMBOL DEFINITIONS
040000
020000

RING=
crS=

040000
020000

000200

RDONE=

000200

000002

DTR=

000002

000200

XRDY=

000200

002000
002002
002004
002006
002010

002000
175610
175612
175614
175616
177564

RCSR:
RBUF:
XCSR:
XBUF:
CXCSR:

.=2000
175610
175612
175614
175616
177564

002012

177566

CXBUF:

177566

002014

000000

BUFFER:

002016

000000

DELAY:

002020

000000

;BIT 14 OF RCSR, RING
;BIT 13 OF RCSR,
;CLEAR TO SEND
;BIT 07 OF RCSR,
;RECEIVER DONE
;BIT 01 OF RCSR, DATA
;TERMINAL READY
;BIT 07 OF XCSR,
;TRANSMITTER READY

;CSR OF RECEIVER
;BUF OF RECEIVER
;CSR OF TRANSMITTER
;BUF OF TRANSMITTER
;CSR OF CONSOLE
;TRANSMITTER
;BUF OF CONSOLE
;TRANSMITTER
;HOLDS CHARACTER
;RECEIVED
;HOLDS DELAY COUNT,
;HIGHORDER
;HOLDS DELAY COUNT,
;LOWORDER

0
;BEGINNING OF ECHO PROGRAM
BEGIN:

CLR

@RCSR

;START BY INITIALIZING
;ALL BITS TO ZERO

LOOPl:

BIT
BEQ

# RING ,@RCSR
LOOP 1

177734

BIS

#DTR,@RCSR

177744

MOV

#5,DELAY

;CHECK FOR INCOMING CALL
;BRANCH IF PHONE IS NOT
;RINGING
;PHONE IS RINGING, SO
;ANSWER WITH DTR
;SET UP COUNT FOR DELAY

002022

005077

177752

002026
002034

032777
001774

040000

177744

002036

052777

000002

002044

012767

000005

4-11

Table 4-7 DLVll-E Programming Example (Cont)
BIT

#CTS,@RCSR

BNE
SUB
SBC

LOOP3
#1,DELAY+2
DELAY

001752

BEQ

BEGIN

002076

000765

LOOP2

002100

032777

BIT

#CTS,@RCSR

002106

001745

BEQ

BEGIN

002110

032777

BIT

#RDONE,@RCSR

002116

001770

BEQ

LOOP3

002120

017767

177656

177666

MOV

@RBUF,BUFFER

002126

032777

000200

177650

BIT

#XRDY,@XCSR

002134
002136

001774
016777

177652

177642

BEQ
MOV

LOOP4
BUFFER,@XBUF

002144

032777

000200

177636

BIT

#XRDY,@CXCSR

002152
002154

001774
016777

177634

177630

BEQ
MOV

LOOPS
BUFFER,@CXBUF

002162

000746

LOOP3

002052

032777

020000

177720

002060
002062
002070

001007
162767
005667

000001
177722

177730

002074

020000

000200

177672

LOOP2:

LOOP3:

177662

LOOP4:

LOOPS:

4-13

;CHECK FOR CLEAR
;TO SEND
;BRANCH IF ON
;CHECK DELAY
;DECREMENT A
;TWO-WORD INTEGER
;BRANCH IF WE HAVE
;WAITED TOO LONG
;BRANCH AND CONTINUE
;TO WAIT FOR CTS
;IS CHANNEL STILL
;ESTABLISHED?
;BRANCH IF CTS NOT
;PRESENT
;CHECK FOR RECEIVED
;CHARACTER
;BRANCH IF NO
;CHARACTER RECEIVED
;READ RECEIVED
;CHARACTER INTO BUFFER
;CHECK FOR TRANSMITTER
;READY
;BRANCH IF NOT READY
;TRANSMIT CHARACTER
;TO REMOTE TERMINAL
;CHECK FOR CONSOLE
;TRANSMITTER READY
;BRANCH IF NOT READY
;TRANSMIT CHARACTER
;TOCONSOLE
;BRANCH AND WAIT FOR
;NEXT CHARACTER

PROGRAMMING ~XAMP~t
THl F~~XI~l~lTY Or
01i!~0&0

.·blt!!

.WORD

INPUT

!IJ011J0~i!

00113"
000340

0000&4

"'iIlla!b

.WORD
.WORP
.WORD

UUTPUT

~000&0

"000&&

"'0~34~

000204

00000~

F~AG31

0\!10001
00i/l002

OUTUON~'2

THt

3HOWING
WITH INTERRUPT3

D~Vl1-f

~RUG~A~MING

~EC~lVER VECTOR
PH I OH IT Y 7
TRAN3MITTER VECTOR
PRIORITY 7

Hill

l411l

.'2"'''

0<102016

rO~

USED A3 TME CO~MUNICATION ~INK
6ETwt~N THE MAIN MOOULE AND
THE INTtRRUPT ROUTINES.

BIT i:J \ TO BE S~T IN
61T 1 I 'MAIN' ~HICH

INl)ONE' 1

~LAGS

TELL
IS DONE,

8IT POSITION O~ THE INT~RRUPT
ENAB~E BIT IN 60TH THE
RC3H AND XC3R

000100

OLAOO.
RCSR.
RtlUF'
XCI>R'
XIIUF.

1775&0
1175&0
1175&2
1775&4
1775&b

1715b0
D~ADD
DLADO+~

PLAOO+'I
ll~AOIJ+b

001000

GIY~

THE

5TAC~

I>OME ROOM

THIS IS' TME MAIN MOOU~~ WHICH CONTROLS THE
INITIA~IZl

THE

F~OW

Of OATA ••• *

STA~K

3TARTI

001~00
0~1000

01070b

001002

1l24b4~

MOV
CMP
I

PC,1i1'
-(SP) ,-(liP)

SET UP THE STACK POINTER
MAKE SURE IT STARTS 8E~OW US.

PRINT INSTRUCTIONS

IN~T~I

11J01(IH!4

0050&7

171174

C~R

0012&4

MOY

001014

~1i?101
~5i!737

000100

1775&4

1101022
001022

05271>7

00~0i:J2

1771511

001030

1l1iJ1714

\;101032
0~ 1032
00\03&

i21050b7

17114b

~1c!701

001347

001042

0050b7

00kllb&

[>0104&
.,010!i2

"ln~2
0~2131

0~U IHl

"010&0

05i!137

000100

0012104
0010113

ROUTIN~

r~Aij:;

6IS

'INST ,n
UNTtNtI,nXCSR

lilT

'OUTUUNE,f~AGS

ij~Q

~~Aijli

1775bll

CLR
MOY
LLR
MOV
6IS

1775bll

SIS

'INTtNt!. 'UCSR

START CLEAN
HI 13 OUR OUTPUT BYTE POINTtH
3ET INTERHUPT ENAa~E IN XCSM

151

WAIT fOR OUTPuT TO FINISH
OuTPUT ROUTINE WILL 3fT BIT
I
1 IN FLAGS WHEN DONE
I INStt.AP Of WAITING WE COULD tiE DOING OTHER PROCESSING HER!

Rt.STRT:

12101535

'PO~M,1o(1

INCUUNT
'~INt.,!(2

.INTt.N~,UHC:liR

Rt:START C~EAN
HI FUR THE OUTPUT BYTE POINTER
INITIA~IZt INPUT COUNTfR
H2 FUR THE INPUT BYTE POINTfR
SET INTERRUPT ENAB~E IN ReSH
AND XC3R
11-5174

Figure 4-6

DLVll-F Programming Example
(Sheet 1 of 3)

4-15

ALL WE CAN DO ~OW I~ WAIT ANO KEEP CHECKING.
80TH TRANSMITTER AND ~tCtIVtR ARE WORKING AT PULL SPEEO.
e010&11
0010&11
1/J1II1074

00131/1

0010711
00111112
1/10111/111

lillll 50 II 7
0U701
0527117

177U2
01/J15.Hi
00i!100

1711450

001114
01/J1114
001122

0~27117

000002

1770112

001374

01/J1124
00112&

000000
01!l0741

ill
1/I~27b7

000003

CMP
liNE

177110

-INDUNtIDUTDONE,FLAGS I ARE THEY BOTH DONE?
I IF NOT, WAIT

i!S

, NOW WE HAVE A LIN~ IN ANU 'H~ PU~M OUT.
CLR
MOV

CL~AN UP AGUN
NOW WE wILL P~INT ~INE
LIOT IT INTERi'lUPT

-OUTUOI\I~,~LAIiS

8IS

IJINTtN~,XC~R

CMP
8NE

LINE TYPED YET?
WE MUST BE PATIENT

HESTln

ALL DONE
TO DO IT AGAIN

3al

,***._-_.*
001130

IN"UTI

1i"'0015
00001i!

tNU OF THE MAIN MODULE ** •• _. ___ •
THIS IS THt: ,NPUT HOUTINE, IT IS INTERRUPT DRIVEN
A5 t:ACH CHAWACTt:R IS RECEIVED 8Y THE DLV11~F AN
INTtHHUPT 15 IitNEi'lATEO,
Ra 15 THE bLuaAL PUINTER TO THE NEXT LOCATION FOR
STOWAIiE O~ TH~ INPUT STREAM.
WHILt IN THllj HUUTIN~ THE PWIORITY IS 7
WHtN A CAHHIAGE ~E'URN IS SEEN, IT IS STORED ANa
A LIN~ ~EtO I~ IN5EHTED AFTtR IT, SINC~ THIS IS
OUR SIGNAL TO STOP W~ WILL CLEAR INTERRUPT
ENA~LE ON THE HCSH AND SET INDONE IN FLAGS,

Cfh

001130
001134
001141/J
001144

113704
1i14i!104
0204i!1
001414

1715112
177&00
0ldil015

1/J011411
001154

0211727
1il3404

0~00bi!

0011511
0011112

0050117
0047117

LF.

Ii!

MOV8
aIC
CMP

'UtlUf,R4

BEQ

_177bll!~,R4

R4,"t.;R
10.

CMP
IILO

000110

0~005i!

000034

IIH'Il1 Il1o

0011Il10
001171/J
001174

FLA(;1j
'LI Nt:,1'I1

,CARRIAGE Rl:TURN
, LINE FEED
SAVE CHARACTER IN REGISTER /I
STRIP OFF PANITY AND JUNK
IS IT A CARRIAGt RETUNN
IF 50, WE'RE DONE
DO WE HAVE 7a CHARACTERS UN THIS LINE
NO~.5KIP AROUND cCRLF~ INSERTION

CLR
JSR

INCUUNT
PC,CWLt

MUVI!
INC

R4,tNi!)+

1 CHARACTER INTO LINE

111

, un

REst T COUNTER
INSERT CRLF

151

11111422
01o!152E07
000411

INCOUNT

, COUNT IT

I THIS CODE WRAPS IT UP AFTEt( RECEIVINIi A CARRIAGt RETURN

0011711
1/1011711
2J1/J121/J2
1/101204
0G11212

0047117
1I/I5P11i!
0427117
052767

1011

1/J01220
001 220

1/10000i!

001222
001222
121 ill i!211
00U32

112722
112722
0lZl1ili!07

001i!34

1il0000i1l

JU
CLRS
8IC

0000i!0
000100
000001

17113411
17117&4

illS

PC,C"'L.~

tRi)

iIIINTtNII,~CIjR

UNI)UNt:,I'LAGS

FINISH LINE
APPEND NULL tlVTE
NO MORE INTERRUPTS
SIGNAL DONE

lUI
RT!

EXIT

CHLFI
001/1015
000012

HOV!:!
MOVII
RTS

iIICR, ~~o!) +

.'v, tNo!l+
PC

INCOUNTI0

CARRIAGE RETU~N
LINE FEEO
RETURN
CHANACTERS PER LINE COUNT
11-5175

Figure 4-6 DLVll-F Programming Example
(Sheet 2 of 3)

4-16

UUTPUTI

'10123&

THIS IS THt UUTPUT ROUTINE
IT ALSU IS INT~~HU~T DRIVfN,
T~IS ~OUTINt IS CA~~ED WHEN THf TRANSMITTER IS READY
TO UUTPUT ANOTHtR CHA~ACTfR,
Rl l~ UUR ~~U8A~ PUINTf~ TO THE LINE O~ OUTPUT,
'OUT~UT' RUN~ AT A PRIORITY Of 1
A NU~L ~YTt 15 THf TERMINATION SIGNA~.
00123&
001242
001244

112137
105711
0Q1100f1

17151111

00124&
001254

0427 37
0';;i!7b7

0011lU0

0.)12&2
0012&2

00000i!

001l1210c

MOV8
TloTS
BNE

l~ 1 J

UNTtNtI,nXCSR

BIC
SIS

1775&4
17H22

THE CHARACTER
NfXT BVTf NULL"
NO-- ~XIT ANO WAIT

TRAN~HIT

'Hll +,"'X~Uf
Ii

NO MURE INTERRUPTS
THE MAIN ROUTINE

.OUTuONt,~~AtjS

TEL~

1$1

fnI

t.XIT

,***.t***_*******_*** __ *_* ••• * ___ • __ * ____ •• ________
I ASCII STORAGt AREAl
0012&4
il0121i1
''01300
0i/!13011
001314
001315
0013C!2
00133121
0013311
001344
01!'1347
001354
12l013b2
001370
f1J<J1376
001401
00140&
001414
10101422
11:01430
0014lb
12101441
0014411
001454
1Il014b2
0<)1470
111314711
0<11501
0121150&
001514
0~15i!i!

201530
001"i35

054524
02011&
1/!4b040
,, 47 105
1'140
127
~2iill~1

<140'511
05~105

2105015
015
"~''!131

i62I1Jl~1

042514
~0&5~2

040
0/1&10&
11'53440
0445U
llil"'li!3
0"1045/1
101
~4"52b
~4il510

04051111
1<)54522
00b5i!4
~4121

04"5111
~51501
0201~S

027117
000
lil;'0001

ITYPI; IN YUUW LINE tNOING I

• ASC II

IWIT~

.ASCII

cCR~CL~~/M.RY

021i11i!3
04i!503
053440
0/10440
053517

.ASCII

i!4i1440
O5344'"
05216/1",
164111515

.ASCII

IANU

• ASC 1Z

THI; LAM~ WAS SUHE TO GO./cCR~cl.f~

STURAG~

"'444140
0511e5
llil0105
04351b

05iHI1
0411503
04i!507
eSllil5

"'SLUe!
051040
1Il2711b

INn:

02011~

"'IDID

04bll12
04i1510
044514
0/111040
01i!
05.! 1 \I
~4c!505

05151211
042524
Z/l71i!3

012
04c!11&
0511522
04i!522
0i!1<!1 24
055440
012
10411124
04111';;
1'151440
.,417524
I00!1015

INSTRUCTIONS, POtH, AND INPUT LINE.

.ASCII

04i!5i!'1
041531
047111
044504

11151101
020104
05i1124
04b501

PU~M:

Il~

._.*t*_

A C~HRIAG~

~~~tCE

~VENY

~.D

WAS

W~ER~

RETURN./cCH~c~f~

A LITTL~

I.AM~/cCR~c~F~

W~ITt

S~OW,/cCR~cI.F~

T~AT

MARY

WENT/cCR.c~f.

~4710!)

162010~

IIl531140
0511i!5
III 4344 "

000
~INEI

.SYT~

~OW

INPUT

L1N~

STARTS HtRE

.t:ND
11- 5176

Figure 4-6

DLVII-F Programming Example
(Sheet 3 of 3)

4-17

4.6 PROGRAMMING NOTES
Several programming considerations are presented below. Additional information is available from
program listings and current software manuals.
1.

Character Format - Figure 4-7 shows the serial character format. Note that when less than
eight data bits are used, the character must be right-justified to the least significant bit. The
character format pertains to both the receiver and the transmitter.

Maintenance Mode - The maintenance mode is selected by setting the MAINT bit (bit 02) in
the XCSR. In this mode, the interface disables the normal input to the receiver and replaces
it with the output of the transmitter. The programmer can then load various bits into the
transmitter and read them back from the receiver to verify proper operation of the DLVII-E
and DLVII-F logic circuits.

Clearing Interrupt Enable Bits - Before executing an instruction that will clear the XCSR or
RCSR interrupt enable bits, the processor should be set to its highest priority (PS bit 7 = 0).
This will prevent the processor from recognizing an XCSR or RCSR interrupt request that
occurs during instruction execution and then erroneously acknowledging that request after
the instruction has cleared it. If the computer were to acknowledge the interrupt request
after the interrupt enable bit has been cleared, it could result in a bus timeout error when the
processor attempts to input a vector from the device.

Programmable Baud Rate - The baud rate is programmed by loading the desired bits into
the high byte of the XCSR and setting bit 11. An example of a program step that does this is:
MOVB #130,XCSR +1 ;300 BAUD BITII ENABLE PROGRAMMABLE

IDLE
STATE OF
NE

0------

I·

START
BIT

1 OR 2

RETURN TO IDLE

"I- BITS~ ~ STATE OF LINE
;o-i-o~~~~i-o;~~;i-o~i~~i-o;
]STOP:STOPU~~ART
BIT OF
LSB
MSB
1
2
NEW CHARACTER
8 DATA BITS

--~--~--~--~--~--~--~-I
-"'i
I-ONE BIT TIME=ONE/BAUD RATE

II -4968

Figure 4-7

Serial Data Format

4-18

CHAPTER 5
DETAILED TECHNICAL DESCRIPTION

5.1 GENERAL
This chapter describes, on a detailed functional level, each of the 12 circuits discussed in Chapter 2.
For a description of the major LSI chips, refer to Appendix A. For circuit schematics, refer to DLVllE Asynchronous Line Interface, Circuit Schematics (DIGITAL part number D-CS-MSOI7-0-1) or to
D L Vll-F Asynchronous Line Interface, Circuit Schematics (DIGITAL part number D-CS-MS02S-0-1).
The functional areas described in this chapter are illustrated individually. It may be helpful, however,
to refer back to Figure 2-3 for a general overview.
5.2 BUS INTERFACE
Four De005 transceiver chips perform the bus interface functions. The chips receive from and transmit to both the computer's Bussed Address/Data Lines (BDALs) and the module's three-state bus
data lines (DATs). The chips decode the module's address from the LSI-ll bus and place interrupt
vectors on the LSI-ll bus.
5.2.1 Address Decoding
The computer addresses the module for both input and output data transfers. A data transfer occurs in
two stages: address time and data time. (These are described further in Paragraph 5.3,1/0 Control
Logic.) During address time the computer places the address on bus lines BDALOO L through
BADL15 L and asserts the memory bank 7 select signal (BBS7 L). This signal indicates that the
address is in the 2S-32K range of addressing space, and enables the DC005 transceiver chips to decode
the address. The circuit performs a logical inversion on the entire address word and places it on the
three-state bus. However, it decodes only bits 03 through 12 (Figure 5-1). Bits 00 through 02 pertain to
device register selection, and are routed to the I/O control logic for decoding. Bits 13 through 15
pertain to the selection of addressing space. Their states are already indicated by BBS7 L. Bits 03
through 12 contain the address of the specific DLVll-E or DLVll-F being addressed. The bus interface's address decoding circuitry compares the states of bits 03 through 12 with the conditions set by
address jumpers A3 through A12. If a match is decoded, the circuit asserts MATCH H to enable the
I/O control logic.
During data time, the transceivers transfer data from the LSI-II bus lines to the three-state bus lines if
the operation is an output data transfer. If the operation is an input data transfer, the I/O control logic
asserts the "in word" signal (INWD L), switching the transceivers to their opposite state, in which they
transfer data from the three-state bus to the LSI-ll bus.
5.2.2 Vector Addressing
The bus interface circuit can place one of two vector addresses on the BDAL lines when the interrupt
function is enabled by the program. Which vector is placed on the bus lines is determined by the
interrupt logic. Bit 02 of the vector word (Figure 5-2) is controlled by VECRQSTB H from the interrupt logic. This bit is in a TRUE state for a transmitter interrupt and is negated for a receiver interrupt.
Bits 03-0S can be selected by the user by removing or inserting vector jumpers V3 through VS. The
remaining bits are all zeros.

5-1

BDAL
BITS ,..-'-1..;..5__r-----___r------ro8~---.,;0;..;.7--__r-----___r-------:O;.::O....,

I 1

BBS7 L

=1III
N

IX)

It)

ADElRESS JUMPERS:
I NSTA LLED =0
REMOVED = 1
o = RECEIVER
}
1 = TRANSM ITTER - - - - '
0= CSR
}
----'
1 = DATA BUFFER
o = LOW BYTE } _ _ _ _---'
1 =HIGHBYTE
RANGE = 1600008 - 1777768
11-4911

Figure 5-1

BDAL
BITS

DLVll-E and DLVll-F Addresses

I ""I I I I

SELECTED BY USER.
It)
cD
~
ASSERTED BY INTERRUPT ~
~
>
>
>
>
LOGIC CIRCUIT. ' ' - - - - - - . . .
y .,------''
VECTOR JUMPERS:
INSTA LLED=O
REMOVED=1

0 =RECEIVER
1 = TRANSMITTER

CONTROLLED BY INTERRUPT
LOGIC CIRCUIT.
RANGE=0-7748
11-4912

Figure 5-2 DLVII-E and DLVll-F Interrupt Vectors

To place a vector on the bus lines, the interrupt logic asserts VECTOR H. VECTOR H enables those
bits whose corresponding vector jumpers have been installed. This action does not require BBS7 L or
INWD L.
S.3 I/O CONTROL LOGIC
The I/O control logic monitors LSI-II bus control signals, decodes the device address from the last
three bits of the address word, and controls the flow of data in the module. The major element in the
I/O control logic is a DCOO4protocol chip. This chip decodes DATOO H through DAT02 H, monitors
VECTOR H from the interrupt logic and MATCH H from the bus interface, and responds to tlJe
following LSI-II bus control lines:
BSYNCL
BWTBTL
BDINL
BDOUTL

Bussed Synchronize
Bussed Write Byte
Bussed Data In
Bussed Data Out
5-2

The chip controls four register select lines for enabling the device registers (Table 5-1). It also generates
OUTHB Land OUTLB L signals to control which byte of a register is loaded. The chip produces the
"in word" signal (INWD L) to control the direction of data flow through the bus interface transceivers. It also generates a reply (BRPLY L) to the LSI-ll bus.

Table 5-1

DAT02H

DATOIH

Select Line
Asserted

Low
Low
High
High

Low
High
Low
High

SELOL
SEL2L
SEL4L
SEL6L

RCSR
RBUF
XCSR
XBUF

5.3.1 Input Operation
When the LSI -11 program reads data in from the D LV 11-E or D LV 11-F to the computer (DATI bus
cycle), the input data transfer proceeds as follows:
1.

The program places the device address on LSI-ll bus lines BDALOO L through BDAL15 L,
and asserts BBS7 L (Figures 5-3 and 5-4). BWTBT L is negated at this time because all input
transfers are full words rather than bytes.

BBS7 L enables the bus interface logic to decode the address. The circuit decodes the address
and sends MATCH H to the I/O control logic. It also inverts the address word and places it
on three-state bus lines DATOO H through DAT15 H. DATOO H through DAT02 Hare
applied to the I/O control logic.

The computer asserts BSYNC L. The leading edge of BSYNC L latches the states of
MATCH Hand DATOO H through DAT02 H into the protocol chip of the I/O control
logic. The chip decodes DATOO H through DAT02 H to recognize the address of the device
register, and then asserts the appropriate register select line. It asserts SEL2 L, for example,
if the program is addressing the RBUF. The register select signal conditions a gate that will
later be enabled for the data transfer .

. 4.

The computer next removes the address from the LSI-II bus lines, negates BBS7 L, and
asserts BDIN L. BDIN L is gated with the register select lines. This enables the selected
register to place its contents on the three-state bus. BDIN L is also routed to the protocol
chip, which asserts INWD L. INWD L causes the bus interface transceivers to transfer the
data from the module's three-state bus to the LSI-II bus. The chip waits about 150 ns for the
data to stabilize on the three-state bus lines and then asserts INWD Land BRPLY L.
BRPLY L signals the computer that the data is on the bus.

The computer reads in the data and then negates BDIN L.

The I/O control logic responds to the negation of BDIN L by negating BRPLY L.

The computer terminates the bus cycle by negating BSYNC L.

In the absence of a TRUE condition on BSYNC L, the protocol chip releases the register
select and INWD L signals. The bus interface reverts to its normal condition of receiving
from the LSI-ll bus and transmitting onto the three-state bus.
5-3

BUS INTERFACE DCOO5

K
A

THREE-STATE BUS

BDALOO -15 L )

...

DATOO-15 H

'\r-

BUS
TRANSCEIVERS
BBS7 L
C/l

0
I

::>

./
RCSR

RBUF

XCSR

0
0

!II

XBUF

!;j:

r-- --- --

H
C/l

..J

I
BSYNC L

BWTBT L

BDIN L
BDOUT L
BRPLY L
'I

ADDRESS
DECODER

/'\

'1'

MATCH H

INWD L

'V'
OUTHB L

n1P

.... OUTLB L

;
I

1-----1-- - - - - I-

I-- -

I-

~ ~~ In II
1' .....

I
I
I
I
_______________ I

PROTOCOL CHIP DCOO4

...,

SEL 0 L

SEL 2 L

I
I
I

SEL 4 L

SEL 6 L

L~~~~~~

11-4913

Figure 5-3

I/O Control Logic, Block Diagram

5-4

R/T DAL

(4)

RADDR

R SYNC
75ns
MIN
R

DIN

RPLY

BS7

25ns
MIN

(4)

j.:=

T DATA
125ns MAX

1;'"

65ns MINMAX

150ns MIN
~ 235nsMAX

150ns MIN==::j1"SIN
65n5
MAX

(4)

X~100ns

(4)

MAX

(4)

25ns MIN
R WTBT

(4)

NOTES:
I. Timing shown at Master and Slave Device
Bus Driver inputs and Bus Receiver Outputs.
2. Signal name prefixes are defined below:
T = Bus Driver Input
R = Bus Receiver Output
3. Bus Driver Output and Bus Receiver Input
signa I names include a "B" pref ix .
4. Don't care condition.
11-4914

Figure 5-4

Data Input Timing

5-5

5.3.2 Output Operation
The DLVII-E and DLVII-F can accept data from the computer in either bytes or words. To write a
word out to the interface module, the computer performs a DATO bus cycle; for a byte, a DATOB bus
cycle. An output data transfer proceeds as follows:
I.

The program places the device address on LSI-II bus lines BDALOO L through BDAL15 L,
and asserts BBS7 L (Figure 5-5). BWTBT L is asserted at this time. (During address time,
BWTBT L is negated for an input operation and asserted for an output operation.) BBS7 L
enables the bus interface to decode the address and send MATCH H to the I/O control
logic. The bus interface also applies DATOO H through DAT02 H to the I/O control logic.

The computer asserts BSYNC L. The leading edge of BSYNC L latches the states of
MATCH Hand DATOO H through DAT02 H into the protocol chip. The chip decodes the
register address and asserts the appropriate select line.

R DAL

_(4_)_---JX

R ADDR

~_ _ _R_DA_"_A_ _ _ _ _J).(

~25nsMIN

(4)

R SYNC
-

.....""1.f--150 ns MIN

R DOUT

RPLY

BS7

_ _--r_ _ _ _+-~--+_r__---------_!;=25ns MIN
R WTBT

ASSERTION • BYTE

j::

(4)

25ns MIN

NOTES:
I. Timino shown at Master and Slave Device
Bus Driver Inputs and Bus Receiver Outputs.
2. Sionai name prefixes are defined below:
T = Bus Driver Input
R • Bus Receiver Output
3. Bus Driver Output and Bus Receiver Input
sionai names include a " e"prefill.
4. Don't care condition.
11-41115

Figure 5-5

Data Output Timing

5·6

The computer removes the address from BDALOO L through BDAL15 L and negates BBS7
L. If a byte is to be transferred out to the device register, BWTBT L remains asserted. If a
word is to be transferred, BWTBT L is negated. At this time the computer places data on the
LSI-II bus lines and asserts BDOUT L. BDOUT L goes to the protocol chip and enables it
to decode the states of BWTBT Land DATOO H. The chip uses these signals to determine
the desired byte of the addressed register (Table 5-2). The device registers are configured for
output transfers unless switched otherwise by BDIN L. Therefore, BDOUT L is not gated
with the register select and byte lines.

Table 5-2

Byte Selection (Output Operations Only)
Select Line

Byte

BWTBTL

DATOO H

Asserted

Selected

High

Don't Care

OUTLBLand
OUTHBL

Both

Low

OUTLBL

Low

High

OUTHBL

High

About 150 ns after it receives BDOUT L, the protocol chip issues BRPLY L to the computer
to signal that the module is loading data.

The computer removes the data from its bus lines and negates BDOUT L.

The protocol chip responds to this by terminating BRPLY L.

The computer then terminates the bus cycle by negating BSYNC L and, if applicable,
BWTBT L.

When BSYNC L is negated, the protocol chip negates the register select and byte select lines.

5.3.3 Vector Operation
The I/O control logic has the additional function of asserting BRPLY L in response to VECTOR H
from the interrupt logic. This action is independent of BSYNC L and MATCH H. It is part of the
interrupt sequence and is discussed further in Paragraph 5.7.
5.4 CONTROL/STATUS REGISTERS
The RCSR and XCSR each consist of several types of flip-flop latches, rather than single devices.
Status bits from various circuits are placed in the registers and then, under the control of the I/O
control logic, gated on to the three-state bus for transfer to the computer. Control bits from the
computer are loaded into the registers from the three-state bus. While in the registers, they direct the
operation of the modules.

5-7

5.4.1 CSR Data Flow
RCSR operation differs between the DLVII-E and DLVll-F only in those areas concerned with the
peripheral interface requirements (Figures 5-6 and 5-7). Some bits are set by the peripheral interface
circuit, receiver active circuit, and the RBUF, while others are set by the program via three-state bus
lines DATOO H through DAT06 H. All RCSR bits except the DLVII-F's Reader Run Enable bit may
be read by the program. Refer to Chapter 4 for a listing of how the bits are set and cleared.

SOURCE

RCSR

----PERIPHERAL
INTERFACE
CIRCUIT

DATA SET
INTERRUPT

DAT15 H

RING

DAT14 H

,.----.

CLEAR
TO SEND

DAT13 H

r-----

CARRIER
DETECT

DAT12 H

reo

RECEIVER
ACTIVE

OATH H

SECONDARY
RECEI VE

DATlO H

RECEIVER
DONE

DATO? H

r-- rRECEIVER
ACTIVE
CIRCUIT

RBUF

DESTINATION

t--

DAT06 H -

RECEIVER
INTERRUPT
ENABLE

DAT05 H -

DATA SET
INTERRUPT
ENABLE

DAT03 H -

SECONDARY
TRANSMIT

DAT02 H -

REQUEST
TO SEND

DATOl H -

DATA
TERMINAL
READY

L--.

INTERRUPT
LOGIC

PERIPHERAL
INTERFACE
CIRCUIT

11-4916

Figure 5-6

DLVII-E RCSR Data Flow

5-8

SOURCE

RECEIVER
ACTIVE
CIRCUIT

RBUF

RCSR

DESTINATION

RECEIVER
ACTIVE

DATU H

RECEIVER
DONE

DAT07 H

DATOS H -

RECEIVER
INTERRUPT
ENABLE

DATOO H -

READER RUN
ENABLE

INTERRUPT
LOGIC

II PERIPHERAL
INTERFACE
CIRCUIT

11-4917

Figure 5-7 DLVII-F RCSR Data Flow

5-9

XCSR operation is the same for both the DLVII-E and the DLVII-F (Figure 5-8). The bits for the
baud rate control circuit are write only bits. TRANSMITTER READY is a read only bit. The other
XCSR bits are both read and write bits.

SOURCE

XCSR

DAT15 H _

PBR
SELECT 3

DATl4 H -

PBR
SELECT 2

DAT13 H _

PBR
SELECT 1

DAT12 H _

PBR
SELECT 0

DATl1 H _

PROGRAMMABLE
BAUD RATE
ENABLE

PROG RAMMABLE
BAUD RA TE SELECT

XBUF

I
I

DATOS H _

TRANSMITTER
READY
TRANSMITTER
INTERRUPT
ENABLE

DESTINATION

BAUD RATE
CONTROL

DAT07

~
_I

INTERRUPT
LOG I C

DAT02 H _ MAINTENANCE
MODE

MAINTENANCE
MODE LOGIC

DATOO H -

BREAK LOGIC

BREAK

11-4918

Figure 5-8 DLVll-E and DLVll-F XCSR Data Flow

5-10

5.4.2 Input Operation
The contents of the RCSR and XCSR are read into the LSI-11 by an input data transfer (DATI). The
computer places the address of the register on the LSI-II bus and then the bus interface and I/O
control logic decode the address. The I/O control logic generates register select signals that switch data
selectors to the desired source (Figure 5-9).
The select signals also enable the output of the data selectors and, if the RCSR is addressed, enable bus
drivers. The status information leaves the CSRs on the three-state bus. The bus interface circuit then
transfers the data to the LSI-II bus.

DATA SELECTORS
74LS257
TRANSMITTER
STATUS
BITS

/~>+---'"--------<-----I

I------------I*-....
RECEIVER
STATUS
BITS

THREE - STATE BUS

I
I

r-----~~>--r---_r---~
DRIVERS'
REGISTER SELECT

1/0
CONTROL
LOGIC
ENABLE

11- 4919

Figure 5-9 Control/Status Registers During DATI

5.4.3 Output Operation
The LSI-II writes control bits out to the CSRs by an output data transfer (DATO or DATOB).
Normally the RCSR is loaded by a DATOB cycle because only the low byte contains control bits. (The
bits used in the high byte are all read only status bits.) The XCSR can be loaded by a DATOB cycle if it
is desired to load only the high byte (e.g., to change the baud rate), or only a low byte. The computer
uses a DA TO cycle to transfer a full word to the XCSR.
When the computer addresses the desired register, the bus interface and I/O control logic circuits
decode the address. The I/O control logic generates register and byte selection signals that enable the
chips comprising the selected register (Figure 5-10). Flip- flops latch in control bits that are held in the
register, and data selectors route other bits to latches in the circuits which they control.
5-11

"
..../

{

TRANSMITTER
CONTROL
LATCHES

TO
TRANSMITTER
CIRCUITS

THREE - STATE BUS

"\/
....

RECEIVER
CONTROL
LATCHES

TO
RECEIVER
CIRCUITS

i
IIO

CONTROL
LOGIC

11-4920

Figure 5-10 ControlfStatus Registers During DATO or DATOB

5.5 DATA BUFFERS
Both transmitter and receiver data buffering functions are performed mainly by a single LSI chip. The
chip is a Universal Asynchronous Receiver/Transmitter (UART). The UART is a double-buffered,
full-duplex receiver/transmitter. The receiver section performs the RBUF function, accepting asynchronous serial binary characters, converting them to parallel format, and placing them on the threestate bus. The transmitter section performs the XBUF function, accepting parallel data from the threestate bus and converting it to a serial aysnchronous output. The receiver strips START, STOP, and
parity bits off the data coming in from the peripheral device. The transmitter appends START, STOP,
and parity bits to the data being transmitted out to the peripheral device. Jumper control of the STOP
and parity bits, and the number of data bits, is defined in Chapter 3.
The UART is driven by a clock signal (or two clock signals, for split speed operation) from the baud
rate control circuit. The clock speed is 16 times the baud rate of the UART. The UART transmitter
internally synchronizes the START bit with the clock input to ensure a full 16-element (clock periods)
START bit independent of the time of data loading. The receiver rejects any received START bit that
lasts less than one-half of a bit time.

5-12

5.5.1 Receiver Operation
Serial data coming in from the peripheral device is converted to TTL levels by the peripheral interface
and is applied to the UART's receiver section (Figure 5-11). The UART samples the serial input data
line at 16 times the data bit rate. The line is in a continuous marking state when idle. When a START
bit arrives, the UART detects the mark-to-space transition and begins loading the received character
into the receiver shift register. The character is shifted to have its least significant bit in the lowest bit
position of the register. If jumpered for checking parity, the UART checks the total of the received
data bits plus the parity bit. (It checks for an even total if even parity has been selected, and an odd
total if odd parity has been selected.) A parity error will result in a flag bit (P ERR) being set (Figure 512).
DATA FORMAT
JUMPERS

UART
DATA BITS
X CLK

R CLK

t - + - -...... PERIPHERAL
INTERFACE
TRANSMITTER

--------RECEIVER

. . . - - - - - - - . SER I A L
PERIPHERAL INPUT
INTERFACE t---+-II--I

11-4921

Figure 5-11

U ART Signal Flow

5-13

PERIPHERAL
INTERFACE

DATA FORMAT
JUMPERS.
RECEIVED DATA
STATUS BITS

...J~

::!;:::l

Q:a.

C\I

LLlZ
CIl_

THREE-STATE
BUS LINES

ILLl

ERROR

DAT15

ERR

OVERRUN
ERROR

DAT14

ERR

FRAMING
ERROR

DAT13

PARliY
ERROR

DAT12

P ERR

1
ERR
RDONE

RCSR
BIT 7

RECEIVED
DATA BITS

UART
(RECEIVER SECTION)

RD8

DAT07

RD7

DAT06

RD6

DAT05

RD5

DAT04

RD4

DAT03

RD3

DAT02

DATOI

RD2
..

RDI

DATOO H

...J

BAUD
RATE
CONTROL

I/O
CONTROL
LOGIC

11- 4922

Figure 5-12

DLV11-E and DLV11-F RBUF Data Flow

5-14

The UART checks the STOP bit to see ifit is marking. If the line is spacing when the UART checks for
a STOP bit, the UART sets the framing error flag (FR ERR).
When the U AR T receives the center of the first STOP bit, it transfers the data in parallel from the
receiver shift register to the holding register. At this time, the data and error bits become available for
gating on to the three-state bus, and the UART asserts the receiver done (ROaNE H) signal. This sets
the RECEIVER DONE status bit in the RCSR.
If the receiver interrupt enable bit is set, RDONE H initiates an interrupt request. The LSI-II then has
a full character period to service the interrupt before the next character moves into the holding register.
During this time the next character is being assembled in the receiver shift register. After an LSI-ll
DATI sequence has taken the data, the I/O control logic resets the receiver done status bit. If the LSI11 program does not take the data before the next character enters the holding register, RDONE H
does not get reset. In this case, the UART sets the data overrun flag (OR ERR). This bit goes with the
next received data word to indicate that the old data was lost.

Any of the three error conditions (Overrun Error, Framing Error, or Parity Error) sets an end check
error flag (ERR) as well as its own flag. These error bits do not initiate an interrupt request, but they
are available in the high byte of the RBUF for the programmer's use.
S.S.2 Transmit Operation
The XBUF consists of two registers and their controlling logic, all of which are contained in the
UART chip. A holding register stores the parallel data taken off the three-state bus, and then transfers
it in parallel to the transmitter shift register. Next, the data is shifted out serially. The format of the
character being transmitted is controlled by the data format jumpers.
During idle time the UART transmits a continuous marking signal and holds the transmitter ready
status bit (XMIT ROY) asserted in the XCSR. XMIT ROY initiates a transmitter interrupt request if
the transmitter interrupt enable bit is set in the XCSR. If the interrupt function is not enabled, the
UART transmitter remains idle until the program requires it.
When the program has data to transmit to a peripheral device, it uses a DATa or DATOB sequence to
address the XBUF and place the data on the bus lines. The bus interface moves the data from BDALOO
L through BDAL07 L to DATOOHthrough DAT07 H. The I/O control logic enables the XBUF to
load the data into its holding register (Figure 5-11). When the data enters the holding register, the
UART negates Xl\1IT ROY. The UART then transfers the data in parallel from the holding register
to the transmitter shift register and reasserts XMIT ROY. In the transmitter shift register, the U ART
attaches the selected StART, STOP, and Parity bits. The assembled character is then shifted serially
out.of the XBUF to the peripheral.interface circuitry (Figure 5-13).
The time between the leading edge of the register select signal from the I/O control logic and the
corresponding m~rk-to-space transition of the serial output line is within one clock cycle (1/16 of a bit
time) if the transmitter has been idle.
XMIl' ROY is asserted as soon a,s a character is transferred from the holding register to the transmitter. shift register, thereby indicating that the holding register is empty. The next character may be
loaded immediately ,even while the first character is still being serially shifted out of the transmitter
shift register. Thus, if the holding register and transmitter shift register' are both empty, the LSI-II can
parallel-transfer a two-character pair into the XBUF in less time than it takes for a single character to
be serially transmitted to the peripheral device. This advantage of double-buffering applies only to the
first two characters; that is, if a series of characters is being transmitted each character after the second
must wait a serial character period for the XBUF to become ready again. The actual time depends on
the baud rate.

5-15

DATA
, FORMAT
JUMPERS

:.:

TRANSMIT DATA BITS

...J
U
X

-Q.IW

DAT07 H

SERIAL , . . . . - - - - . . ,
OUTPUT PERIPHERAL
, INTERFACE

DATOS H
DAT05 H
OAT04 H
DAT03 H

UART
(TRANSMITTER SECTIQNI

DAT02 H

XMIT
ROY

DATOl H
DATOO H

11-4923

Figure5-13

DLVll-E and bLVll-F XBUFDa,ta'Flow

5.6RECEIVE.R ACTIVE CIRCUIT'
,
'
,
The receiver active circuit produces a status, bit to indicate that the RBUF is receiving a character of
data. This status bit, RECEIVER ACTIVE, is set by the START bit of the received data character and
cleared by the receiver done (RDONE H) signal from the UART. "
During th~ period between received data characters, SI MARl< H from the peripheral interface holds
the receiver clock counterin the cleared state (Figure5-14). When a START ~it is received, SI MARK
H,changes state and releases the CLEAR line to the counter. The counter begins to"count receiver
clock pulses from the baud rate, control ch,cuit. Each RCLK:H pulse is 1/16th of a bit time. The
counter counts to eight, which places it in the center of the START bit, then asserts RBUSY H.
RBUSY H is routed to the RCSR, where it can be read in by the program I;lS' RECEIVER ACTIVE. It
is also used to stop the counter and to inhibit SI MARK H from clearing the counter. When the RBUF
has finished receiving the character, the UART asserts RPONE H. RDONE H clears the counter,
thereby negating RBUSY H a,nd returning the circuit ,to .its' initial condition. Thus, RECEIVER
ACTIVE is set during the time from the center of the START bit to the lead~ng edge of R DONE H.
5.7 INTERRUPT LOGIC
' ,,'
Both transmitter and receiver interrupt functions ofthe,intetrupt logic are handled by asingle DC003
interrupt chip. This chip is described in Appendix A. The intequpf lpgic has a receiver interrupt
channel, a transmitter interrupt channel, iind control circuitry. Figu,re 5-15 shows the signal flow
,"
"
,
associated with the interruptfhip.

5-16

.---------------,
BAUDRATEr-~----~----__----------~
CONTROL

R BUSY H

I
I
I

RCSR
BIT '1

COUNTER

COUNT ENABLE

PERIPHERAL
INTERFACE

SI MARK H

CLEAR

L _ _ _ _ __
MAl NT
MODE
DATA
ISELECTOR

RCSR
BIT 7

r- ' - - - - -.... RBUF

R DONEH

~~~~~----------------------~

THREE - STATE BUS

::>
11- 4924

Figure 5-14

Receiver Active Circuit

5.7.1 DLVll-E Receiver Interrupts
In the DLVII-E, a receiver interrupt sequence is started by either the UART or the peripheral interface circuitry. Both cases require that the appropriate enabling bit be set in the RCSR. When the
computer program sets RECEIVER INTERRUPT ENABLE (bit 06) in the RCSR, an interrupt can
be caused by RDONE H from the UART. The UART asserts RDONE H when the RBUF has
received and assembled a character of data. When the program sets DATA SET INTERRUPT
ENABLE (bit 05) in the RCSR, an interrupt can be initiated by DATA SET INTERRUPT from the
peripheral interface circuit. The peripheral interface sets DATA SET INTERRUPT when it receives
control signals from a data set. When either pair of conditions is satisfied, the receiver channel will be
enabled to request to interrupt the program. When the interrupt is acknowledged (discussed in Paragraph 5.7.4), the interrupt chip asserts VECTOR H. This signal causes the assertion of the vector
address bits that correspond to the vector jumpers which the user has inserted. The bus interface circuit
places the bits set by jumpers V3 through V8 onto LSI-ll bus lines BDAL03 L through BADL08 L.
All other BDAL's are negated at this time. When the computer locates the service routine, it may
check the status bits in the RCSR to determine what condition initiated the interrupt. Refer to Paragraphs 4.3 and 4.6 for notes regarding simultaneous receiver and data set interrupt conditions.

5-17

PART OF
RCSR
IPERIPHERALL DSET INT H
INTERFACE

R DONE H
UART

I XMIT

ROY H

FROM
COMPUTER
VIA
THREESTATE
BUS

{"TOOH
DAT06 H

DATA SET
INT *

BIT 151

RCVR
DONE

BIT 7

RCVR INT
ENB

BIT 6

DSET INT
ENB*

BIT 5

I
I
I
I

BDAL 15 L
BDAL 14 L
BDAL 13 L
BDAL 12 L

BDAL 11 L

~ CONTROL
I/O

BDAL 10 L
VECTOR
ADDRESS
JUMPERS

LOGIC

I
- ~ XMIT ROY

BIT 7

XMIT
INT ENB

BIT 6

BRPLY 2

PART OF
XCSR

B IAKI L
III
::;)

I
I

B I AKO L

D-

BDAL09 L

La: BDALoa L

a::
UJ

I-

~V7)0- z

r--l
'"

I XMTR
I CHANNEL

RCVR
CHANNEL

BDAL07 L

III

V6 )0- ::;) BDAL06 L

r-JV5L

BDAL05 L

(V4)
f--o 0 -

BDAL04 L

----!V3)o-

BDAL03 L

III
::;)

::
1
H
III

...J

BDAL02 L

BDIN

(va)

r-:-<>

H
III

BDALOI L

...J

BINIT L

BIRO L

CONTROL
CIRCUITS

VECTOR H
VEC ROST B H

BDALOO L

IL.. _ _ _ _ _ _ _ _ .JI

L--

* DATA SET INT AND DSET INT ENB
APPLY TO DLVll-E ONLY.
11- 4925

Figure 5-15

Interrupt Vector Signal Flow

5.7.2 DLVll-F Receiver Interrupts
The DLV11-F interrupt vector flow is the same as that of the DLV11-E, with the exception that it has
no DATA SET INTERRUPT or DATA SET INTERRUPT ENABLE bits. The module does not
support data set control, and therefore produces a receiver interrupt only for servicing the RBUF.

5-18

S. 7.3 Transmitter Interrupts
The DLVII-E and DLVII-F function alike for transmitter interrupts. The interrupt logic generates a
transmitter interrupt when the program sets TRANSMITTER INTERRUPT ENABLE (bit 06) in the
XCSR and the UART asserts XMIT RDY H. The UART asserts XMIT RDY H when the XBUF is
empty and ready for more data from the computer. When XMIT RDY H and TRANSMITTER
INTERRUPT ENABLE are both TRUE, the transmitter channel of the interrupt chip is enabled to
request interrupt service. (Although these two signals are functionally bits 06 and 07 of the XCSR, they
are physically located in the interrupt chip.) After the computer acknowledges the interrupt logic's
interrupt request, the circuit asserts both VECTOR Hand VECRQSTB H. VECTOR H is applied to
vector address jumpers V3 through V8, the same as for a receiver interrupt vector. In this case, however, VECRQSTB H causes the bus interface to assert BDAL02 L, as well as the other selected bits on
BDAL03 L through BDAL08 L. This results in the vector addressing of the transmitter interrupt
service routine.
S. 7.4 Interrupt Transactions
Either type of interrupt begins with the interrupt logic asserting BIRQ L, the interrupt request line.
This is followed by an interchange of control signals and the vector address being placed on the LSI-II
bus lines. The sequence proceeds as follows:
1.

The request is initiated by the interrupt logic asserting BIRQ L (Figure 5-16).

1j-________
INTERRUPT LATENCY
MINUS SERVICE TIME

-+1_50_0~_~_~_~N"X

T IRQ

DIN

R IAKI

T RPLY

-------------+----j--f i I25 ns MAX.
T DAL

------------------+----t-------'

1-II00ns

i-I------\.I
MAX.
VECTOR

195n5 MIN
320n8 MAX

R SYNC

(UNASSERTED)
15ns MIN
65ns MAX

R BS7

(UNASSERTEDI
NOTES:
1. Timing shown at Requesting Device Bus Driver Inputs and Bus Receiver Outputs.
2. Signal Name Prefixes are defined below:
T = Bus Driver Input
R = Bus Receiver Output
3. Bus Driver Output and Bus Receiver Input signal names include a II Boo prefix.
11-4926

Figure 5-16 Interrupt Timing
5-19

The LSI-ll responds to BIRQ L by asserting BDIN L and then BIAKI L.

BIAKI L is passed down the priority chain until it reaches the section of the interrupt logic
that initiated the request. When the circuit receives both BDIN Land BIAKI L, it asserts
VECTOR H (and also VECRQSTB H, if a transmitter interrupt) and negates BIRQ L.

, 4.

VECTOR H cause$ the I/O control logic to issue BRPLY L to the computer. VECTOR H
(and VECRQSTB H, if applicable) also causes the bus interface to place the vector on the
LSI-ll bus lines.
.

The computer reads in the interrupt vector and then, as a result of receiving BRPLY L,
negates BDIN L. Shortly after this it also negates BIAKI L.

The interrupt logic negates VECTOR H (and VECRQSTB H, if applicable).

The negation of VECTOR H causes.the I/O control logic to negate BRPLY L, and the bus
interface to remove the vector from the LSI-ll bus lines.

An interrupt transaction does not require MATCH H, BSYNC L, BBS7 L, or INWD L. The interrupt
logic overrides the module's normal I/O protocol. When the computer is initialized, the interrupt logic
is cleared by BINIT L.

5.8 BAUD RATE CONTROL
The baud rate control circuit establishes the speeds at which the RBUF and XBUF operate. The
circuit consists of two sets of wire wrap jumpers, gating circuitry, an oscillator, and a 5016 dual baud
rate generator. The 5016 chip divides the oscillator frequency down to the frequency selected by the
jumpers or the program. In the split speed mode of operation, it produces two separate clock frequencies: one for transmit and one for receive. The circuit routes either these clocks or an external clock to
the UART to control the baud rate(s) at which the module operates.
Also included in the baud rate control are gates that decode a selection of 110 baud. When this
condition is detected, the circuit asserts 110 BAUD H. This signal enables the UART to handle a data
format having two STOP bits (Figure 5-17).

5.8.1 Program Control
The 5016 chip has two sections, each of which is driven by a 5.0688 MHz clock from the oscillator. The
two sections of the chip each divide the 5.0688 MHz clock by a selectable amount. The selection for
section B of the chip is accomplished by jumpers TO through T3. The frequency in section A, however,
can be controlled byeither jumpers RO through R3 or three-state bus lines DAT12 H through DAT15
H. The source of control for section A of the chip is selected by a data selector chip. This data selector
is functionally part of the high byte of the XCSR. It is addressed by a combination of the Programmable Baud Rate Enable bit (on DATIl H) and register select lines from the I/O control logic. If
DATll H is asserted during a. DATO output transaction, the data selector chip will route the logic
states ofDAT12 H through DAT15 H to the dual baud rate Generator chip to program the frequency.
When DATIl H is not asserted, the data selector chip will select jumpers RO through R3 to control the
dual baud rate generator.
When computer power is first switched on, the assertion of BDCOK L causes the data selector to select
jumpers RO through R3 as the source of the section A frequency control. From that time on the circuit
can choose either the jumpers or the XCSR bits, asdetermined by the state of the Programmable Baud
Rate Enable bit. A table of jumper combinations. and their corresponding baud rates is presented in
Chapter 3.

5·20

r""
5016
BAUD RATE
GENERATOR

DAT12 H
THROUGH
DATI5 H

)...

THREESTATE
BUS

R¢
THROUGH
R3 --".

RECEIVE
JUMPERS

/
v

CONN CLK
INPUT H

l....".....

FOUR BIT
DATA SELECTOR

lrrl

DATil H (PS)

BDCOK L -

SECTION
A

BKI

~
------

I
I

TRANSMIT
JUMPERS

T!1J
THROUGH
T3
"

(CI)

( SIl

I--

SECTION
B

I
f---.

I-

BHl
EXT TCLK H

5.0688MHz
OSC

CONN CLK
EN L

RCLK H

XCSR

UART

(S)

~TCLK H

MAINT H

L-

II
DATA
FORMAT
JUMPERS

VI
IV

CLOCK
CONTROL
MULTI PLEXER

(MT)!

.[;

GATING

B~
(

MSPARE B

I/O
CONTROL
LOGIC

110 BAUD
DECODE

110 BAUD H
11- 4927

Figure 5-17

Baud Rate Control Signal Flow

5.8.2 Jumper Control
When the Programmable Baud Rate Enable bit is not set, section A of the 5016 chip is controlled by
jumpers RO through R3. This section is used to control the receiver baud rate during split speed
operation. During common speed operation, section A (and jumpers RO through R3) controls both
transmitter and receiver baud rates.
Jumpers TO through T3 always determine the output frequency of section B of the chip. During split
speed operation, this establishes the baud rate of the transmitter. During common speed operation,
jumpers TO through T3 and section B of the chip are not used. When the module is operating in its
maintenance mode and in split speed, TO through T3 and section B produce the clock for both the
RBUF and the XBUF.
5.8.3 External Control
External clock inputs can be introduced through either the backplane connector or the header connector. Pins BKI and BLl are connected together by a jumper (MSPAREB) at each module location
on the LSI-II backplane. The output of section A is routed through this jumper.
The jumper can be cut and an external clock applied to backplane pin BLl. This clock will then drive
the receiver in split speed operation, or both the receiver and the transmitter in common speed
operation.
An external clock can be used for the transmitter in split speed operation by removing jumper SI and
applying the external clock to backplane pin BH 1. External clock frequencies must be 16 times the
desired baud rate.
The baud rate can be controlled by an external peripheral device via the cable to the module's header
connector. When a TTL logic low enabling signal is applitd to 11 pin HH it causes the clock control
multiplexer to select the external clock on pin Cc. When the enabling signal is negated the baud rate
reverts to its former configuration.
5.8.4 Clock Selection
The receiver and transmitter clock inputs to the RBUF and XBUF timing circuitry (in the UART) are
selected by two jumpers and a multiplexer. Normally the multiplexer selects the input from pin BLI as
the receiver clock. The CONN CLK EN L signal, however, causes the multiplexer to select header
connector pin CC as the receiver clock. Additionally, during the maintenance mode only, MAINT H
causes the multiplexer to choose the transmitter clock as the source of the receiver clock in split speed
operation, and the receiver clock as the source of the transmitter clock in common speed operation
when jumper MT is installed.
During split speed operation, jumpers Sand S 1 are inserted and jumpers C and Cl are removed. This
routes the receiver clock to the RBUF section of the UART, and the transmitter clock to the XBUF
section. For common speed operation, jumpers Sand SI are removed and jumpers C and Cl are
inserted. This routes the receiver clock to both the RBUF and XBUF sections of the UART.
Table 5-3 summarizes the possible connections discussed in this section.
5.9 BREAK LOGIC
The break logic performs two functions: it causes a BREAK to be transmitted, and it determines the
action taken when a framing error or a BREAK is received.

5-23

Table 5-3 UART Clock Sources
Clock Source

Receiver Speed

Transmitter Speed

Dual Baud Rate Generator
Common Speed
Split Speed

RO-R3
RO-R3

RO-R3
TO-T3

BLl
BLl

BLl
BHI

External Clock on Backplane
Common Speed
Split Speed
External Clock on
Header Connector
Common Speed Only
(Requires Enable on pin HH)

5.9.1 Receive Operation
During normal operation, the UART checks each received character for the proper number of STOP
bits. It does this by testing for a marking condition at the appropriate time. If it finds a spacing
condition instead, it sets the framing error flag (FR ERR). The BREAK signal is a continuous spacing
condition, and is interpreted by the UART as a data character that is missing its STOP bites). The
UART, therefore, responds to the BREAK signal by asserting FR ERR H (Figure 5-18). MAINT L
from the XCSR is gated with FR ERR H to inhibit the framing error signal (FE H) during the
maintenance mode.FE H is applied to jumper B, and is inverted and applied to jumper H. If jumper B
is inserted and -B (or B) is removed, FE H will negate control line BnCOK H. BnCOK H indicates to
the LSI-II that dc power is "OK." When FE H negates this signal, it causes the computer to reload its
bootstrap.
If jumper B is removed and jumper -B (or13) is inserted, the computer will not "boot" on a framing
error.
If jumper H is inserted, FE H will negate control line BHALT L. This causes the computer to halt
when a framing error is received.

CAUTION
If the LSI-ll is using MOS memory, data may be

lost when BDCOK·H is negated because this action
interrupts the memory refresh cycle.
5.9.2 Transmit Operation
To transmit a BREAK signal the program sets the BREAK bit (bit 00) in the XCSR (Figure 5-19). The
output of the XCSR latch holding the BREAK bit is used to inhibit the serial data output of the
. XBUF. This causes the peripheral interface circuitry to transmit a continuous spacing condition
(BREAK signal) on the serial communications line.
BREAK generation can be enabled by inserting jumper BG. This allows the state of nATOO H
(BREAK bit) to control the BREAK inhibit gate. When the BREAK bit is set, BREAK(O) L is
clocked to a continuous FALSE condition, thus inhibiting the flow of serial data from the XBUF to
the peripheral interface.
5-24

XCSR
BIT 2
MAINT L

(Hlo BHALT L

.. API

FE H

FR ERR H

UART

.X>_BD_C,-O_K_H_ B Al

RBUF
DATA
SELECTOR

11- 4928

Figure 5-18

Break Logic Receive Signal Flow

DATOO H _
XCSR
BIT 0

IIO
CONTROL
LOGIC

(BGI

...--

BREAK (01 L

XBUF

BREAK
INHIBIT
GATE

SO MARK H

PERIPHERAL
INTERFACE

SERIAL OUT H

" -4929

Figure 5-19 Break Logic Transmit Signal Flow

. S.10 MAINTENANCE MODE LOGIC
In the maintenance mode, the DLVll-E and DLVll-F modules route their output data back to their
input (Figure 5-20). To accomplish this the computer program sets the MAINTENANCE bit in the
XCSR. The latch holding this bit has two outputs. One goes to the break logic to prevent the generation of framing error signals during operation in the maintenance mode. The other output is applied
to the maintenance mode data selector. The data selector normally routes the incoming data from the
peripheral interface to the RBUF. In the maintenance mode, however, it switches its input to the
output of the XBUF. This action loops the serial data out of the XBUF back into the RBUF and
disconnects the peripheral interface's received data. While in the maintenance mode, the serial output
of the XBUF continues to go to the peripheral interface and out to the peripheral device.

5-25

MAINTENANCE MODE
DATA SELECTOR
PERIPHERAL
INTERFACE

SI MARK H
SERIAL IN H

XBUF

SO MARK H

RBUF

I
I
I
I
I
I

PERIPHERAL
INTERFACE
MAINT H

DAT02 H XCSR
BIT 2
I/O
CONTROL
LOGIC

MAINT L

•

BREAK
LOGIC
,,-4930

Figure 5-20

Maintenance Mode Logic

5.11 DLVll-E PERIPHERAL INTERFACE
The DLVll-E provides data set control by producing and responding to EIA-compatible control
signals. EIA-Ievel receivers in the peripheral interface circuit monitor the following control lines:
RING, CLEAR TO SEND, CARRIER, and SECONDARY RECEIVED DATA (Figure 5-21). Each
of these control lines is represented by a bit in the RCSR. The peripheral interface will set the DATA
SET INTERRUPT bit in the RCSR if RING changes state from a 0 to ai, or if any of the three other
signals changes state from either a 0 to a 1 or a 1 to a O. Thus, when the computer program has set
DSET INT ENB, a signal on any of the incoming EIA control lines can initiate a receiver interrupt.
When the interrupt is acknowledged, the program can check the RCSR to determine which signal
initiated it. The program can then respond by asserting the appropriate control bits in the RCSR. The
peripheral interface responds to a True condition on RCSR bits 1, 2, or 3 (DATA TERMINAL
READY, REQUEST TO SEND, and SECONDARY TRANSMITTED DATA, respectively) by
transmitting a TRUE condition on the corresponding EIA control line. (If the data set has a FORCE
BUSY function, jumper FB should be inserted to drive this control line with the REQUEST TO
SEND bit.) The exchange of control signals allows a remote data set to establish a channel of communication with the LSI-11 through the use of a handshake.
A typical handshake sequence proceeds as follows: A remote data set calls the local data set. The local
data set sends a RING signal to the DLVI1-E asynchronous line interface. The RING signal initiates a
receiver interrupt (assuming DSET INT ENB is set). The program reads the RCSR and determines
that the interrupt was caused by the RING signal. Then, through a service routine, it issues the DATA
TERMINAL READY and REQUEST TO SEND signals. These signals direct the local data set to
answer the remote data set by sending it a carrier signal. The remote data set acknowledges the carrier
signal by returning its own carrier signal. The local data set detects the remote data set's carrier signal
and indicates this to the D LV 11-E by asserting its CARRIER control line. This causes another
receiver interrupt. Upon recognizing the CARRIER-caused interrupt, the program can either receive
or transmit data. The only prerequisites for this handshaking sequence are that the program use appropriate service routines and that the data set interrupt enable bit be set in the RCSR.

5-26

DLVll-E
MC05C MODEM CABLE
DATA SET
r---------------~~--------------~, r~----------~·~----~----~, r~----~4----~
XBUF

[>>-__ I

'--------'
RCSR
BIT

#r------....,
15

BERG
---;.Jl!...« F IJI TRANSMITTED DATA
" 1

I -_ _ _....,...

TTL/E IA
LEVEL
CONVERTER

DATA SET
INTERRUPT
EIA/TTL

I
I
I

I
I

f-r-- BA
l
I
I
I
I
I
I
I
I
I
I
I ( 2 2 f t - - CE

RING

I---+---+-< X ~ I RING INDICATOR

CLEAR
TO SEND

I---t---t-< T ( I CLEAR TO SEND

CARRIER
DETECT

I---t---t-< BB f-~-+-~CA::.:R.:..:.R!.!.IE:=.!R~______________H( 8

I ( 5 ft-- CB
I

ft--- CF
I
I

5~~18Ml~~b~

CINCH
Pl ( 2

I-----_K JJ f-~-+-.;::.S=-EC~O:..:.N::.=D.:...:A.:..:.RY.:......:.:R.=.EC::..::E:..:..IV:....:E::.::D:....;D:..:..A.:..:.T.:...:A---+-« 16

SECONDARY
RECEIVE

ft-- SBB
I
I
I
I

...---;--( A h....;P'-'R.:..:O:...:.T.:.EC=-T.:...:I~VE=-.:G:..:.R:..::Oc.:U.:..:.N=-D__--.,.

8
PROTECTIVE GROUND

SIGNAL GROUND
1--;--( B ~---=-=.:..:=-===-----------rl<
7 'I

TTL/EIA
3

REQUEST
TO SEND

:=----+-<FF~ I SECONDARY TRANSMITTED DATA

~--o-+-( V ~ I REQUEST TO SEND

o...o--o--r-< C ~ I

DATA
TERMINAL
READY

FORCE BUSY

>------+~DD~ I DATA TERMINAL READY

~
I

( 14
( 4

ft-- SBA
ft-- CA
I

(25

T-

(20

ft-- CD

I
I
f-~-+II_R~E::..:C~E:..:..IV:...:E:.::D---=:DA.:...:T.:...:A-----.I.....« 3 ~ BB

______+!I-« J

RBUF

I
I
I
I

I
I
I

4
SECONDARY
TRANSM IT

I--;--(UU~---=-S.:..:IG~N.:...:A=-L~G~R=-O=-UN~D~-----J

DSET
INT ENB

L
L
'I

1-~~vv~~~~~~~~~------tK

1<
I

J
I

......I-----------L,--« E

EIA
INTERLOCK

II -4931

Figure 5-21

DLVll-E Peripheral Interface Signal Flow

5-27

Other exchanges involving CLEAR TO SEND and SECONDARY RECEIVED DATA may be programmed, as required, by the equipment.
SECONDAR Y RECEIVED DATA and SECONDARY TRANSMITTED DATA are provided for
the exchange of secondary or supervisory data with data sets having this capability. SECONDARY
RECEIVED DATA allows the remote data set to set one bit in the RCSR and to cause a receiver
interrupt. SECONDARY TRANSMITTED DATA allows the LSI-ll to transmit the state of one bit
in the RCSR to the remote data set. These exchanges involve only two RCSR bits and are independent
of normal data exchanges between the peripheral device and the DLVll-E's data buffer registers.
EIA-Ievel data from the data set arrives at the DLVII-E on the RECEIVED DATA line. The peripheral interface converts it to TTL levels and routes it to the RBUF. Data to be transmitted from the
computer to the data set is serialized in the XBUF and then routed to the peripheral interface. The
interface circuitry converts it to the EIA-Ievels and transmits it out the TRANSMITTED DATA line
to the data set.
5.12 DLVll-F PERIPHERAL INTERFACE
The DLVII-F supports either EIA data leads ("Data Leads Only" operation) or 20 rnA current loops.
It does not perform handshakes or exchange control signals with data sets.
5.12.1 EIA Data Leads Only Operation
The DLVI1-F does not monitor EIA control lines but it does, however, hold three outgoing EIA
control lines in a continuous TRUE condition. REQUEST TO SEND, FORCE BUSY, and DATA
TERMINAL READY are held continuously TRUE by separate EIA drivers (Figure 5-22). The
peripheral interface converts data from TTL levels to EIA levels for transmission on the TRANSMITTED DATA line. Data received over the RECEIVED DATA line is converted from EIA levels to
TTL levels and routed through an interlock jumper to the RBUF.
DLVll-F

BC05C MODEM CABLE
A

REQUEST TO SEND

v)
C)

DO)

•

: DATA TERMINAL READY.

I
I
I

XBUF

•

I
I FORCE BUSY

~ J

> I TRANSMITTED DATA

> I RECEIVED DATA

RBUF ..

:. ~
I

rlJ

ElA INTERLOCK

11- 4932

Figure 5-22

Data Lead Only Interface
5-28

5.12.2 Current Loop Operation
The peripheral interface directly interfaces terminal devices that use 20 rnA current loops. It provides
current for receiver and transmitter circuits, and also controls the paper tape reader on teleprinters
equipped with a Reader Run relay. Both the transmitter and receiver circuits use neutral current loops,
in that current flows in only one direction (as opposed to polar current loops, in which it flows either
way).
The transmitter can be jumpered for active operation by inserting jumpers 4A and 5A (Figure 5-23), or
for passive operation by inserting jumpers 3P and 4P. In active operation, the transmitter provides
20 rnA (nominal) current to loop through the peripheral device. The current is switched on and off by
data bits from the XBUF.
In passive operation, data bits from the XBUF are optically isolated from the transmission lines.
Through the isolator, the data controls a switching circuit that switches the 20 rnA current on and off.
In passive operation, the peripheral device provides the power for the current flow.
The reader run circuit supplies a negative voltage (approximately -12 V) and a positive voltage
(approximately +5 V) to energize the peripheral device's reader run relay. If the READER ENABLE
bit is set in the RCSR, the reader run circuit causes the peripheral terminal's paper tape reader to
advance. When the START bit of the next character is received, the Receiver Active circuit asserts
RCVR BUSY H. RCVR BUSY H clears the reader enable bit, thereby switching off the current to the
peripheral terminal's reader run relay. The reader run bit must be set again by the program before the
reader run circuit can drive the relay again.
The receiver circuit can be jumpered to be either active or passive. When configured for active operation (Figure 5-24) the circuit supplies a ground and a positive voltage to the peripheral device. When
jumpered for passive operation (Figure 5-25), the receiver uses power supplied by the peripheral
device. In either case, current passes through an optical isolator. The isolator produces a TTL output
that is electrically isolated from the current loop. The TTL output is routed to the RBUF.
The RBUF accepts TTL inputs from either the EIA interface circuit or the 20 rnA circuit. The routing
is determined by the cable attached to the 40-pin header connector (Figure 5-26). An EIA modem
cable will jumper the output of the 20 rnA receiver to the input of the RBUF.
5.13 DC-TO-DC POWER INVERTER
The power inverter operates on +12 V from the LSI-ll power supply and produces -12 V for the
UART, the EIA drivers, and, on the DLVll-F, the reader run circuit. The power inverter circuit
consists of an oscillator driving a charge pump.
The output of the oscillator is capacitively coupled to a rectifier, which develops a negative-going
output. This output pumps up an inductive charge storage network and is Zener-regulated back to
-12 V.

5-29

DLV11·F
____________________________________
~A~__________________________________~
,.

+5V

BC05M CABLE
~
~~

+12V

PART OF
ACTIVE
TRANSMITTER

SERIAL

......::>A:.-._ _ _ _ _-o_14_A_)O_..,Jl-+ AA )>-,.-_O_UT-,-I+.;..)-4••
13P)

XBUF

TRANSMIT
DATA

SWITCHING
CIRCUIT

PASSIVE TRANSMITTER
14P)

15A)

r----------C~-C~~~KK)

SERIAL
OUT 1-)

•

PART OF
ACTIVE
TRANSMITTER

+5V

DATOOH
RCSR
REGISTER SELECT

BIT 0

READER
READER
RUN

RUN (+) ••
......:..-..+ PP )>-..:...--......;...~

L..-_ _ _ _ _ _ _ _ _

RELAY DRIVER
RCVR
BUSY H
READER

1/0
CONTROL
LOGIC

~----------------~_)~EE)~~R~U_N~I-~)-..

RECEIVER
ACTIVE
CIRCUIT

·12V

11-4933

Figure 5-23

20 rnA Transmitter and Reader Run Circuit

5-30

+5V

+12V

(IAI

C29
O.005,..F

J 1'7 K
'----()-(2_A<>1--:r

FOR TTY
ONLY

>-T-- (+ I
, SERIAL DATA IN

(3AI

~S>-r-(-l

1-=

I
I

,
,

:1J

20mA RECEIVED DATA

RBUF

TTL SERIAL DATA IN I ,

20mA INTERLOCK

11-4934

Figure 5-24 Active Receive 20 rnA Current Loop

+5V

(IPI Jl

K)--,- (+1

C29
O.005,..F

,SERIAL DATA IN

(2PI

FOR TTY
ONLY

'-----(>--<>-~S>----r(-)

,
I

,I
,

:1J
I

20mA/TTL RECEIVED DATA

,
I

RBUF

TTL SERIAL DATA IN I ,

20mA INTERLOCK

II -4935

Figure 5-25

Passive Receive 20 rnA Current Loop
5-31

INTERFACE CABLE

DLVII-F PERIPHERAL INTERFACE

,..------.

OF E IA DATA
I
I PART
LEADS ONLY CIRCU ITRY

I
I
I
I

J,'7 J >-______-,r-~E~I~A_R~E~C~E~IV~E~D~D~A~T~A________~~--

. -_ _ _ _ _ _ _ _ _ _L -_ _ _ _ _ _ _ _ _ _ _ _ _ _ _

EIA/TTL
LEVEL
CONVERTER

PART OF
BC05C CABLE

~-----+----------------~M

I'- _ _ _ _ _ ...J

.'UF

....

1~4~-----T-T-L--S-E-RI-A-L-I-N----_r~

)

-----~

OF 20 MA CURRENTI
PART OF
I PART
LOOP CIRCUITRY
BC05M CABLE
I
I
20 MA SERIAL DATA IN (+1
I
ACTIVE
OR
PASSIVE
I
•
RECEIVER
r-+-----------------'-7S ~------~~~2~0~M~A~S~ER~I~A~L~D~A~TA~I~N~(--~I----~--II

.-------------~---------------r7H

1---1-----------------'-7 K

I _ _ _ _ _ ..J
~

II - 4936

Figure 5-26 Interlock Jumper Data Flow

5-32

APPENDIX A
IC DESCRIPTIONS

A.I DCOO3 INTERRUPT LOGIC
The interrupt chip is an 18-pin DIP device that provides the circuits to perform an interrupt transaction in a computer system that uses a "pass-the-pulse" type arbitration scheme. The device is used in
peripheral interfaces and provides two interrupt channels labeled "A" and "B," with the A section at a
higher priority than the B section. Bus signals use high-impedance input circuits or high-drive opencollector outputs, which allows the device to directly attach to the computer systems bus. Maximum
current required from the Vee supply is 140 rnA.
Figure A-I is a simplified logic diagram of the DCOO3 IC. Timing for the A interrupt section is shown
in Figure A-2, while Figure A-3 shows the timing for both A and B interrupt sections. Table A-I
describes the signals and pins of the DCOO3 by pin and signal name.
A.2 DCOO4 PROTOCOL LOGIC
The protocol chip is a 20-pin DIP device that functions as a register selector, providing the signals
necessary to control data flow into and out of up to four word registers (8 bytes). Bus signals can
directly attach to the device because receivers and drivers are provided on the chip. An RC delay
circuit is provided to slow the response of the peripheral interface to data transfer requests. The circuit
is designed such that if tight tolerance is not required, then only an externallK +20 percent resistor is
necessary. External RCs can be added to vary the delay. Maximum current required from the Vee
supply is 120 rnA.
Figure A-4 is a simplified logic diagram of the DC004 IC. Signal timing with respect to different loads
are tabularized in Table A-2 and are shown in Figure A-5. Figure A-6 shows the loading for the test
conditions in Table A-2. Signal and pin definitions for the DCOO4 are presented in Table A-3.
A.3 DCOOS TRANSCEIVER LOGIC
The 4-bit transceiver is a 20 pin DIP, low-power Schottky device for primary use in peripheral device
interfaces, functioning as a bidirectional buffer between a data bus and peripheral device logic. In
addition to the isolation function, the device also provides a comparison circuit for address selection
and a constant generator, useful for interrupt vector addresses. The bus I/O port provides high-impedance inputs and high-drive (70 rnA) open-collector outputs to allow direct connection to a computer's
data bus structure. On the peripheral device side, a bidirectional port is also provided, with standard
TTL inputs and 20 rnA tristate drivers. Data on this port is the logical inversion of the data on the bus
side.
Three address jumper inputs are used to compare against three bus inputs and to generate the signal
MATCH. The MATCH output is open-collector, which allows the output of several transceiver's to be
wired-anded to form a composite address match signal. The address jumpers can also be put into a
third logical state that disconnects that jumper from the address match, allowing for "don't care"
address bits. In addition to the three address jumper inputs, a fourth high-impedance input line is used
to enable/disable the MATCH output.

A-I

Three vector jumper inputs are used to generate a constant that can be passed to the computer bus.
The three inputs directly drive three of the bus lines, overriding the action of the control lines.
Two control signals are decoded to give three operational states: receive data, transmit data, and
disable.
Maximum current required from the Vee supply is 100 rnA.
Figure A-7 is a simplified logic diagram of the DC005 IC. Timing for the various functions is shown in
Figure A-8. Signal and pin definitions for the DC005 are presented in Table A-4.

A-2

+VCC-@
+VCC

16 ENAST H

ROSTA H
SET
ENAOATA H

ENACLK H 14

C
0
CLR

VCC
ROSTA H
ENAST H
ENAOATA H
ENACLK H
ENBCLK H
ENBOATAH
ENBST H
ROSTB H

VECTOR H
VECROSTB H
BOIN L
INITO L
BINIT L
BIAKO L
BIAKI L
BIRO L
GNO

C
CLR

BIAKI L 07
BIAKO L

BINIT L

BIRO L

BOIN L

ENBST H
VECTOR H

ENBCLK H 13

0
CLR

+VCC
ROSTB H 10

C
0
CLR

~GNO

INITO L
IC - 0173

Figure A-I

DC003 Simplified Logic Diagram

~?? 1300 :

BINIT L

INITO L

~
-+t
,

~MINI
I
I
1
I
7-35

--~I----------------------------------------------------------------------

I
I
I

I
ENA DATA H

,,
1

ENA CLK H

MIN~ ~~____________________________-Jr---l~

___________________________

I
ENA ST H

7-30~

ROSTA H

BIRO L

, b -'--;:,.......F 20 - 90

15-65-':

L..____

BDIN L

BIAKI L

35 MIN--:

t:....,-_.....,
F-i r1
,

VECTOR H

35 MIN--

1
1

10-45-:

10 - 45

,,
,

, r-~

12-55--1

BIAKO L

12-55

NOTE:
Times are in nanoseconds
11-4150

Figure A-2

De003 "A" Interrupt Section Timing Diagram

A-5

BIN IT L

00300:
MIN
MIN I
~

I
I
I

I ~~I------------------------------------12-50
~
I
I
I

INITO L 7-35

1
1

ENB DATA H
I

I
ENB CLK H

Fl
I

30 MIN - . ;

I
1

ENB ST H

7-30-:

BIRQ L

L--_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _

15 7 6 5 - :
I
I

~--------------------------------------------------

RQSTB H

ENA DATA H
1

--1 F
1

ENA CLK H

30 MIN

ENA ST H

RQSTA H

B DINL

35 MIN--l

BIAKI L

t:J
1
1

1
1

35 MIN - - \

t::
1
:

L_rb
1--1
11 1_0_-4_5_ _ _ _ _ _
10_-_4_5-i:--'-,

VECTOR H _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _10_-_4_5.:..11......

1 ...

I
I
I

VECRQSTB H

15 - 65:=--:1

:=1

10 - 45

l==-=! 15-65

NOTE:
Times are in nanoseconds
11-4151

Figure A-3

De003 "A" and "B" Interrupt Section Timing Diagram

A-6

Table A-I
Pin

DCOO3 Pin/Signal Descriptions

Signal

Description

VECTORH

INTERRUPT VECTOR GATING signal. This signal should
be used to gate the appropriate vector address onto the bus and
to form the bus signal called BRPLY L.

VECRQSTBH

VECTOR REQUEST "B" signal. When asserted, indicates
RQST "B" service vector address is required. When unasserted,
indicates RQST "A" service vector address is required. VECTOR H is the gating signal for the entire vector address. VEC
RQST B H is normally bit 2 of the vector address.

BDINL

BUS DATA IN. This signal, generated by the processor BDIN,
always precedes a BIAK signal.

INITO L

INITIALIZE OUT signal. This is the buffered BINIT L signal
used in the device interface for general initialization.

BINITL

BUS INITIALIZE signal. When asserted, this signal brings all
driven lines to their unasserted state (except INITO L).

BIAKOL

BUS INTERRUPT ACKNOWLEDGE signal (OUT). This
signal is the daisy-chained signal that is passed by all devices not
requesting interrupt service (see BIAKI L). Once passed by a
device, it must remain passed until a new BIAKI L is generated.

BIAKIL

BUS INTERRUPT ACKNOWLEDGE signal (IN). This signal is the processor's response to BIRQ L true. This signal is
daisy-chained such that the first requesting device blocks the
signal propagation while nonrequesting devices pass the signal
on as BIAKO L to the next device in the chain. The leading edge
of BIAKI L causes BIRQ L to be unasserted by the requesting
device.

BIRQL

ASYNCHRONOUS BUS INTERRUPT REQUEST from a
device needing interrupt service. The request is generated by a
true RQST signal along with the associated true interrupt
enable signal. The request is removed after the acceptance of the
BDIN L signal and on the leading edge of the BIAKI L signal,
or the removal of the associated interrupt enable, or due to the
removal of the associated request signal.

10
17

REQSTBH
REQSTAH

DEVICE INTERRUPT REQUEST SIGNAL. When asserted,
with the enable "A" flip-flop asserted, will cause the assertion
of BIRQ L on the bus. This signal line normally remains
asserted until the request is serviced.

A-7

Table A-I

DC003 Pin/Signal Descriptions (Cont)

Signal

Description

11
16

ENBSTH
ENASTH

INTERRUPT ENABLE "A" STATUS signal. This signal
indicates the state of the interrupt enable "A" internal flip-flop,
which is controlled by the signal line ENA DATA H and the
ENA CLK H clock line.

12
15

ENBDATAH
ENADATAH

INTERRUPT ENABLE "A" DATA signal. The level on this
line, in conjunction with the ENA CLK H signal, determines
the state of the internal interrupt enable "A" flip-flop. The output of this flip-flop is monitored by the ENA ST H signal.

13
14

ENBCLKH
ENACLKH

INTERRUPT ENABLE "A" CLOCK. When asserted (on the
positive edge), interrupt enable "A" flip-flop assumes the state
of the ENA DATA H signal line.

A-8

VECTOR H
BDAL2 L
BDALI L
BDALO L
BWTBT L
BSYNC L
BDIN L
BRPLY L
BDOUT L
GND

VCC
ENB H
RXCXH
SEL6 L
SEL4 L
SEL2 L
SELO L
OUTHB L
OUTLB L
INWD L

........-vvv- +VCC
ENB H

I--~-----~D

BSYNC L

X~-.---IG

BDAL2 L

I~------_.----------------------,
ENS
LATCH

§-- GND

21--------I-~

BDAL 1 L

~ VCC

031--------I-~D

______-+________________________~D~A~L~2

1
Ot

LATCH
DAL 1
O~------~--------------------~~~

10---417

SEL 6 L

b-----I16

SEL 4 L

1O----~15

SEL 2 L

10----114

SEL 0 L

DECODER

OUTHB
OUTLB

RXCX H

BRPLY
BDOUT L

VECTOR

BDIN L

INWD L
Ie-01

Figure A-4

A-9

DC004 Simplified Logic Diagrar

Table A-2 DC004 Signal Timing vs Output Loading
With
Respect
Signal
to

Se1 (0,2,4,6) L

CX=220pf±l%

Output
Being
Asserted
Min
Max
(ns)

Figure A-S
Ref.

Load B
Load C

15
15

35
40

5
5

25
30

t5' t6

BDOUT L

Load B
Load C

5
5

25
30

5
5

25
30

t9' tlO

DBOUT L

Load B
LoadC

5
5

25
30

5
5

25
30

t9' tlO

INWDL

BDIN L

Load A
Load B

5
5

25
30

5
5

25
30

t11,t12

BRPLY L
(Load A)

OUTLB L
(Load B)

-10

BRPLY L
(Load A)

OUTHB L
(Load B)

BRPLY L
(Load A)

INWDL
(Load B)

BRPLY L
(Load A)

VECTORH

BRPLY L
(Load A)

OUTHB L

Pin 18
Connection
RX = 4.64K ±1%

Signal

Output
Being
Asserted
Max
Min
(ns)

BSYNC L

OUTLB L

Pin 18
Connection
RX= IK ±5%
350n ±5%
15 pf±5%

Test
Condo

t13' t14

-10

OUTLB L
(Load B)

300

400

-10

BRPLY L
(Load A)

OUTHBL
(Load B)

300

400

-10

BRPLY L
(Load A)

INWDL
(Load B)

300

400

-10

BRPLY L
(Load A)

VECTORH

330

t13' tl4

t13' t14

A-ll

430

t13' t14

BDAL (2,l,O)L

ENB

~25 MINI25MIN~

H~J~N ~~N~

BSYNC L

I
I

~T6F

SEL (0,2,4,6) L

BWBTL~

1
1
1

BDOUT L

1
I

I __
I~-_____~~.------*----~-L15 MIN.-:!..

15 MIN.--l
I

1
I

I+-

1
1

OUTHB L _ _ _ _ _ _ _ _ _ _ _ _--i1i--,
OUTLB L

--l t=

BDIN L

---'Tll~

-\ no F

100..------* - - - - -........1
1
.....___-

I
I

IWD L

--\T12F
1

--l ~L-

BRPLY L

T13

2.4 V

I
1

11+. --*-----+1-1

I
I
I

4 F

Rx C x H

_I._1~~

_ _ _ _--'_.;..!

I
I

VECTOR H

T15

---1

L~
_ _ _ _ _ _ _ _ _ _ _ __

* TIME REQUIRED TO DISCHARGE Rx Cx FROM ANY CONDITION ASSERTED = 150ns
NOTE:
Times are In nanoseconds
11- 4348

Figure A-5

DC004 Timing Diagram

A-13

Vee

60n

280n

FROM
OUTPUT

FROM )
OUTPUT

roc

rOO'F

DIODE FD777

150,F

-=
LOAD A

LOAD

LOAD C
11-4349

Figure A-6

DC004 Loading Configuration for Table A-2

Table A-3
Pin

DC004 Pin/Signal Descriptions

Signal

Description

VECTORH

VECTOR. This input causes BRPL Y L to be generated through
the delay circuit. Independent of BSYNC Land ENB H.

3
4

BDAL2 L
BDALl L
BDALOL

BUS DATA ADDRESS LINES. These signals are latched at
the assert edge of BSYNC L. Lines 2 and I are decoded for the
select outputs; line 0 is used for byte selection.

BWTBTL

BUS WRITE/BYTE. While the BDOUT L input is asserted,
this signal indicates a byte or word operation: Asserted = byte,
unasserted = word. Decoded with BOUT L and latched
BDALO L to form OUTLB Land OUTHB L.

BSYNCL

BUS SYNCHRONIZE. At the assert edge of this signal,
address information is trapped in four latches. While unasserted, disables all outputs except the vector term of BRPLY L.

BDINL

BUS DATA IN. This is a strobing signal to effect a data input
transaction. Generates BRPL Y L through the delay circuit and
INWD L.

A-14

Table A-3

DC004 Pin/Signal Descriptions (Cont)

Signal

Description

BRPLYL

BUS REPLY. This signal is generated through an RC delay by
VECTOR H, and strobed by BDIN L or BDOUT L, and
BSYNC L and latched ENB H.

BDOUTL

BUS DATA OUT. This is a strobing signal to effect a data
output transaction. Decoded with BWTBT Land BDALO to
form OUTLB Land OUTHB L. Generates BRPLY L through
the delay circuit.

INWDL

IN WORD. Used to gate (read) data from a selected register on
to the data bus. Enabled by BSYNC L and strobed by BDIN L.

OUTHBL
OUTLBL

OUT LOW BYTE, OUT HIGH BYTE. Used to load (write)
data into the lower, higher, or both bytes of a selected register.
Enabled by BSYNC L and decode of BWTBT L and latched
BDALO L, and strobed by BDOUT L.

SELOL
SEL2L
SEL4L
SEL6L

SELECT LINES. One of these four signals is true as a function
of BDAL2 Land BDALl L if ENB H is asserted at the assert
edge of BSYNC L. They indicate that a word register has been
selected for a data transaction. These signals never become
asserted except at the assertion of BSYNC L (then only if ENB
H is asserted at that time) and, once asserted, are not un asserted
until BSYNC L becomes unasserted.

RXCX

EXTERNAL RESISTOR CAPACITOR NODE. This node is
provided to vary the delay between the BDIN L, BDOUT L,
and VECTOR H inputs and BRPLY L output. The external
resistor should be tied to VCC and the capacitor to ground. As
an output, it is the logical inversion of BRPLY L.

ENBH

ENABLE. This signal is latched at the asserted edge of BSYNC
L and is used to enable the select outputs and the address term
ofBRPLY L.

14
15

A-IS

JAI L
JA2 L
MATCH H
REC H
XMIT H
DAn H
DAT2 H
BUS3 L
BUS2 L
GND

VCC
JA3 L
DATO H
DATI H
JV3 H
JV2 H
JVI H
MENB L
BUSO L
BUSI L

JA3 L
~--+---------------------~----,03

MATCH H

MENB L

§]-VCC

GND

Figure A -7

Ie - OC005

DC005 Simplified Logic Diagram

A-16

TRANSMIT DATA TO

BUS

XMIT H

REC H (GROUND)

5 TO 30n.

------------------------------------------1

BUS L - OUTPUT

I- -I

5 TO 25no-l
OAT H - INPUT - - - - - . - - - - - - ;..

1
1-5 TO 25no

1___---IIr----'-----r----

RECEIVE DATA FROM BUS <BUS INITIALLY HIGH)
XMIT H (GROUND)

J-I

REC H _ _ _ _ _ _

OAT H - OUTPUT

::j
0 TO 30no
-I
I- 0 TO 30no
--~---~J!I---------~~

BUS L-INPUT

-----,...-------11'--___________'--__

-I

I-BT030n.

RECEIVE DATA FROM BUS <BUS INITIALLY LOW)
XMIT

H (GROUND)

REC H

OAT H - OUTPUT

----------1I
-l

I+- 0 TO 30n.

--.J

II-

-l

i-OTO 30n.

B TO 30no

BUS L-INPUT

VECTOR TRANSFER TO BUS

JV H

-l

I - 20no MAX

BUS L - OUTPUT

I - 20no MAX

ADDRESS DECODING

X
-1

BUS L - INPUT

MATCH H

__________

-l

MENB L

j+- to TO 40no

~--~----------J

1-5 TO 40no

-I

~ to

TO 40no

RECEIVE MODE LOGIC DELAY
XMIT H

REC H

I- 40 TO 90no

..JI'--______________

DAT(3:0) H (OUTPUT) _ _ _ _ _ _ _ _ _ _ _

fI-4892

Figure A-8

DCOO5 Timing Diagram

A-17

Table A-4

DC005 Pin/Signal Descriptions

Name

Function

12
11
9
8

BUS(3:0) L
BUSO
BUSI
BUS2
BUS3

BUS DATA. This set of four lines constitutes the bus side of the
transceiver. Open-collector outputs; high-impedance inputs.
LOW = 1.

18
17
7
6

DAT(3:0)H
DATO
DATI
DAT2
DAT3

PERIPHERAL DEVICE DATA. These four tri-state lines carry the inverted received data from BUS (3:0) when the transceiver is in the receive mode. When in transmit data mode, the
data carried on these lines is passed inverted to BUS (3:0).
When in the disabled mode, these lines go open (hi-z).
HIGH = 1.

JV (3: 1) H
JVl
JV2
JV3

VECTOR JUMPERS. These inputs, with internal pull-down
resistors, directly drive BUS (3: 1). A low or open on the jumper
pin will cause an open condition on the corresponding BUS pin
if XMIT H is low. A high will cause a one (low) to be transmitted on the BUS pin. Note that BUSO L is not controlled by
any jumper input.

MENBL

MATCH ENABLE. A low on this line will enable the MATCH
output. A high will force MATCH low, overriding the match
circuit.

MATCHH

ADDRESS MATCH. When BUS (3:1) match with the state of
J A (3: 1) and MENB L is low, this output is open; otherwise, it is
low.

JA(3:1)L
JAI L
JA2- L
JA3-L

ADDRESS JUMPERS. A strap to ground on these inputs will
allow a match to occur with a one (low) on the corresponding
BUS line; an open will allow a match with a zero (high); a strap
to Vee will disconnect the corresponding address bit from the
comparison.

XMITH

CONTROL INPUTS. These lines control the operational of the
transceiver as follows:

RECH

REC XMIT

o
o
1
1

o
1
o
1

DISABLE: BUS, DAT open
XMIT DATA; DAT Bus
RECEIVE: BUS DAT
RECEIVE: BUS DAT

To avoid tristate overlap conditions, an internal circuit delays
the change of modes between XMIT DATA mode, and delays
tristate drivers on the DAT lines from enabling. This action is
independent of the DISABLE mode.

A-18

A.4 UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER
The Universal Asynchronous Receiver/Transmitter (UART) is an LSI subsystem that accepts binary
characters from either a terminal device or a computer and receives or transmits these characters with
appended control and error detecting bits. In order to make this subsystem universal, the baud rate,
bits per word, parity mode, and number of STOP bits are selected by external logic circuits.
The UART is a full duplex receiver/transmitter. The receiver section accepts asynchronous serial
binary characters and converts them to a parallel format. The transmitter section accepts parallel
binary characters from the bus and converts them to a serial asynchronous output with START and
STOP bits added.
All UART characters contain a START bit, five to eight DATA bits, one or two STOP bits, and a
PARITY bit which may be odd, even, or turned off. The STOP bits are opposite in polarity to the
START bit. Refer to Figure A-9.
Both the receiver and transmitter are double buffered. The U AR T internally synchronizes the START
bit with the clock input to ensure a full 16-element (clock periods) START bit independent of the time
of data loading. Transmitter distortion (assuming perfect clock input) is less than 3 percent on any bit
up to 10K baud. The receiver strobes the input bit within ±8 percent of the theoretical center of the bit.
The receiver also rejects any ST ART bit that lasts less than one-half of a bit time.

IDLE
STATE OF

I·

~ ;o-i-o~ ~~~~-o~~~~~-o~-:-~~~-o;
NE

8 DATA BITS

·1·

LSB .1. __ ..1. __ .1 __ .1 __ .L __ ..L __ ..L__
MSB
___

0-- - - - START
BIT

-I

1 OR 2

BITS~

]STOP:STOP
1 1 2

RETURN TO IDLE

~STATE OF LINE

U~~ART
BIT OF
NEW CHARACTER

I--ONE BIT TIME=ONE/BAUD RATE
II ~4968

Figure A-9

UART Data Format

A.4.1 Receiver Operation
A block diagram of the UART receiver is shown in Figure A-1O. When the receiver is in the idle state,
it samples the serial input line (SERIAL IN, pin 20) at the selected clock edges (R eLK, pin 17) after
the first mark-to-space transition of the serial input line. If the first sample is a mark (high), the
receiver returns to the idle state and is ready to detect another mark-to-space transition. If, however,
the first sample is a space (low), then the receiver enters the data entry state.
If the receiver control logic has not been conditioned to the no parity state (a low on pin 35), then the
receiver checks the parity of the data bits plus the parity bit following the data bits and compares it
with the parity sense on the parity select line (pin 39). If the parity sense of the received character
differs from the parity of the UART control logic, then the receive parity error line (P ERR, pin 13)
goes high and causes the P ERR bit in the RBUF register to set.
If the receiver control logic has been conditioned to the no parity state (a high on pin 35), then the
receiver takes no action with respect to parity and maintains the parity error line (P ERR, pin 13) in
the FALSE (low) state~ When the control logic senses a parity error, it generates a P ERR signal. The
DATA A VAILABLE signal updates the parity error indicator.

A-19

STATUS
WORD
ENB
AND GATES

DATA BITS

XMIT
BUF
EMPTY

~-----------..

--,

I
I
I

DATA
ENABLE
(RDE)

--.J
SHOWN AS
SINGLE BUFFERING

SERIAL
DATA
INPUT

RCV
CLOCK
INPUT

EVEN
PARITY
SELECT

NO
PARITY

NB2
NB1
NUMBER OF
BITS/CHARACTER
11-4970

Figure A-lO

UART Receiver - Block Diagram

The receiver samples the first STOP bit that occurs either after the PARITY bit, or after the data bits if
no parity is selected. If a valid (high) STOP bit exists, no further action is taken. If, however, the STOP
bit is FALSE (low), indicating an invalid STOP code, then the UART control logic provides a framing
error indication (a high on FR ERR, pin 14).
Because the serial input from the external device is shifted into the U AR T a bit at a time (SI, pin 20),
occurrence of a STOP code indicates that the entire data character has been received and shifted into
the receiver shift register. After the STOP bit has been sampled, the receiver control logic parallel
transfers the contents of the shift register into the receiver data holding register and then sets the data
available (R DONE) flag.
The data available signal also functions as the clock input to the FRAME ERR, PARITY, and
OVERRUN flip-flops in the UART status register. At this point, the DA flip-flop is set, the OVERRUN flip-flop is clear but has a high on the data input because of the output from the DA flip-flop,
and the PARITY and FRAME ERR flip-flops are set or cleared depending on the signal (TRUE or
FALSE) strobed in from the control logic.
An OVERRUN condition indicates that another data character is being sent to the UART before the
previous character has been transferred out. Ifthe DA flip-flop is set, indicating a character is stored in
the holding register, and the UART control logic attempts to set the DA flip-flop again (indicating a
new character has been shifted into the shift register), the DA signal from the control logic provides a
clock input to the OVERRUN flip-flop. This flip-flop then sets because the data input is high (DA
flip-flop was already set by the previous DAsignal).
A-20

If the serial input line goes from a mark (high) to a space (low) and remains at the low level, the
receiver shifts in one character, which is all spaces, then sets the FR ERR indicator and waits until the
input line goes high (marking) before shifting in another character.
A.4.2

Transmitter Operation

A block diagram of the UART transmitter is shown in Figure A-II. When the UART transmitter is in
the idle state, the serial output line (pin 25) is a mark (high). When it is desired to transmit data, a
parallel character is strobed into the UART transmitter data buffer (lines connected to pins 26-33) by
means of the data strobe signal (pin 23). The time between the low-to-high transition of data strobe
and the corresponding mark-to-space transition of the serial output line is within one clock cycle (1/16
of a bit time) if the transmitter has been idle.

NO. STOP BITS
EVEN PAR. SEL.

CONTROL
LOGIC

SERIAL
OUTPUT

END OF
CHARACTER
(EOC)

OUTPUT
LOGIC
DBB
DB7

ENCODER

DB6
DATA
BITS

DB5

XMTR
SHIFT
REGISTER

DATA
BUFFER

DB4
DB3
DB2

LOAD

DB1
DATA STROBE

SHIFT

1-_ _----1f--_t---'-'TR.::::A::..:N:::,:SM:.:.:.IT.:..,:T..=E:..:..R..:;:B::;:.:UF...:..F.o:.:ER.:...=.E:.::.:MP,-,T...:..Y_ _+2.2.~~~~~MITTER

(XRDY)

TBMT
F/F

CLOCK INPUT

11-4971

Figure A-ll

UART Transmitter - Block Diagram

A-21

When the data has been loaded into the UART data buffer, it is next transferred to the transmitter
shift register under control of signals from an encoder that selects the format determined by the control
logic. This permits selection of parity or no parity (pin 35), the type of parity (pin 39), the number of
STOP bits (pin 36), and the number of data bits per character (pins 37 and 38).
The end-of-character (pin 24) signal goes high each time a full character (including STOP bits) is
transmitted. If this line goes low, it prevents the timing generator from loading another character into
the shift register. The line is normally high when data is not being transmitted and goes low at the start
of transmission of the next character.
If the transmitter data buffer is loaded while the previous character is being shifted through to the
output line, the START bit of the new character immediately follows theJast STOP bit of the previous
character.
Figure A-12 shows the pin locations and Table A-5 defines the pin functions.

11-5036

Figure A-12

UART Pin Locations

A-22

Table A-S UART Pin Functions
Pin No.

I/O

Name

Vcc POWER SUPPLY

Vcc

+5 V supply.

Vgg POWER SUPPLY

Vgg

-12 V supply.

GROUND

Ground

RECEIVED DATA ENABLE

RDE

A low on the receiver enable line places the
received data onto the output lines.

5-12

RECEIVED DATA BITS

RDS-RDl

These are the eight data output lines. These
lines may be wire-ORed. When 5, 6, or 7 level
code is selected, the most significant unused
bits are low. Characters will be right justified
into the least significant bits. RD I (pin 12)
is the least significant bit, RDS (pin 5) is the
most significant bit. A high indicates a mark.

RECEIVE PARITY ERROR

PER

This line goes to a high if the received character parity does not agree with the selected
POE.

FRAMING ERROR

FER

This line goes to a high if the received character
has no valid stop bit, i.e., the bit following
the parity bit is not marking.

OVERRUN

This line goes to a high if the previously
received character is not read (DA line not
reset) before the present character is transferred to the receiver holding register.

STATUS WORD ENABLE

SWE

A low on this line places the status word bit
(PE, DA, TBMT, FE, OR) onto the output
lines.

RECEIVER CLOCK LINE

RCP

This line is for a clock whose frequency is
16 times (16X) the desired receiver baud
rate.

RESET DATA AVAILABLE

RDA

A low on this line will reset the DA line.

RECEIVED DATA AVAILABLE

This line goes to high when an entire character
has been received and transferred to the receiver
holding register.

Mnemonic

A-23

Function

Table A·5 UART Pin Functions (Cont)
Name

Mnemonic

Function

Pin No.

I/O

NO PARITY

A high on this lead will eliminate the parity
bit from the transmitted and received character.
The stop bits will immeidately follow the last
data bit on transmission. The receiver will
not check parity or reception. It will, when
asserted, also clamp the PE to a low.

TWO STOP BITS

2SB

This lead will select the number of stop bits,
one or two, to be appended immediately
after the parity bit. A low will insert one
stop bit and a high will insert two stop bits.

37-38

NUMBER OF BITS/CHARACTER

NB2, NBI

These two leads will be internally coded to
select either 5, 6, 7, or 8 data bits/character.
NB2

(37)

NBI

(38)

Bits/Character

0
0

(L)
(L)

(L)

(H)
(H)

0
I
0
I

5
6
7
8

(H)
(L)

(H)

EVEN PARITY SELECT

PEV

The logic level on this pin selects the type
of parity that will be appended immediately
after the data bits. It also determines the parity
that will be checked by the receiver. A low
will insert and check odd parity and a high
will insert and check even parity.

TRANSMITTER

TCP

This line is for a clock whose frequency is
16 times (16X) the desired transmitter baud
rate.

A-25

Table A-5 UART Pin Functions (Cont)
Name

Mnemonic

Function

Pin No.

I/O

SERIAL INPUT

This line accepts the serial bit input stream.
A high must be present when data is not
being received. High is a mark. Low is a space.

EXTERNAL RESET

A high level pulse on this pin will reset TSO,
TRMT, and EOC to a high level and RDA,
PER, FER, and ROR to a low level.

TRANSMITTER BUFFER EMPTY

TBMT

The transmitter buffer empty flag goes to a
high when the data bits holding register may
be loaded with another character.

DATA STROBE

A low to high transition on this line will
enter the data bits into the data bits holding
register. Data loading is controlled by the
rising edge of DS.

END OF CHARACTER

EOC

This line goes to a high each time a full
character including stop bits is transmitted.
It remains at this level until the start of
transmission of the next character. Start of
transmission is defined as the mark to space
transmission of the start bit. It remains at a
high when data is not being transmitted.

SERIAL OUTPUT

This line serially, by bit, provides the entire
transmitted character. It remains at a high when
no data is being transmitted. High is a mark;
low is a space.

26-33

DATA BIT INPUTS

DBI-DB8

These are the eight parallel data input lines.
If 5,6, or 7 bits are transmitted, the least
most significant bits are used. DB I is the
least most significant bit (pin 26). DB8 is the
most significant bit (pin 33). A high input
will cause a mark (high) to be transmitted.

CONTROL STROBE

A high on this lead will enter the control bits
(POE, NB I, NB2, SB, NP) into the control
bits holding register. This line can be strobed
or hard wired to a high level.

A-27

A.5 5016 DUAL BAUD RATE GENERATOR
The 5016 is an LSI MaS device containing two independent sections. Each section divides its input
clock frequency by one of 16 divisors to produce one of 16 different clock outputs. The divisors are
stored in ROMs on the chip. The ROMs are addressed by circuits that latch in and decode the logical
states of the address lines (Figure A-13). The address lines may be strobed or held at a dc level. Table
A-6lists the frequencies selected by the address lines. Figure A-14 depicts the 5016 pin locations. Table
A-7 defines their functions.

STT

+
LATCH
AND
DECODE
CIRCUITS

-----'"

ROM

'-/

J DIVIDER ~ f---

CLOCK

DIVIDER

}- -

STX

+
.....

LATCH
AND
DECODE
CIRCUITS

ROM
y

J
11-4972

Figure A-13

5016 Block Diagram

A-29

CLOCK

VCC

STT

STR

GNO

VOO

NC
11-4973

Figure A-14

Table A-6

5016 Selectable Frequencies
Theoretical
Frequency
16X Clock (kHz)

Actual
Frequency
16X Clock (kHz)

Divisor

0.8
1.2
1.76
2.l52
2.4
4.8
9.6
19.2
28.8
32.0
38.4
57.4
76.8
115.2
153.6
307.2

0.8
1.2
1.76
2.1523
2.4
4.8
9.6
19.2
28.8
32.081
38.4
57.6
76.8
115.2
153.6
316.8

6336
4224
2880
2355
2112
1056
528
264
176
158
132
88
66
44
33
16

Transmit/Receive
Address
B
D
C

Baud
Rate

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

50
75
110
134.5
150
300
600
1200
1800
2000
2400
3600
4800
7200
9600
19200

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1

0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1

5016 Pin Locations

Crystal Frequency = 5.0688 MHz

A-30

TableA-7 5016 Pin Functions
Pin No.

Mnemonic

Name

Function

CLOCK

External Clock
Input

This input is either one pin of a crystal oscillator package or one polarity of another external
input.

Vcc

Power Supply

+5 V supply.

Reciever Output
Frequency

This output runs at the frequency selected
by the receiver address.

RA , R B, Rc> RD

Receiver Address

The logic levels on these inputs select the
receiver output frequency, fRo

STR

Strobe-Receiver
Address

A high level input strobe loads the receiver
address (RA , RB, Rc> RD) into the latch and
decode circuits. This input may be strobed
or hard wired to a high level.

VDD

Power Supply

+12 V supply.

No Connection

GND

Ground

STT

Strobe-Transmitter Address

A high level input strobe loads the transmitter
address (TA' T B' T c> T D) into the latch and
decode circuits. This input may be strobed or
hard wired to a high level.

13-16

T D, TO T B, TA

Transmitter
Address

The logic levels on these inputs select the
transmitter output frequency, fT'

Transmitter
Output
Frequency

This output runs at the frequency selected by
the transmitter address.

CLOCK

Inverted External
Clock Input

This input is either one pin of a crystal package or one polarity of another external input.

4-7

A-31

APPENDIX B
WIRE WRAP INSTRUCTIONS

B.1 PURPOSE
This appendix is intended to assist the user who installs or removes wire wrap jumpers. It describes and
illustrates the preferred procedures and standards for producing high-grade solderless wrapped jumper
wire connections.
B.2 DEFINITIONS
The following terms are used in discussing wire wrapping:
Solderless wrapped connection- This connection consists of a helix of continuous, solid uninsulated
wire tightly wrapped around a wire wrap pin to produce a mechanically and electrically stable connection. In addition to the length of uninsulated wire wrapped around the wire wrap pin, a half turn of
insulated wire is wrapped around the pin to ensure better vibration characteristics (Figure B-1).

TAPERED TIP ON
THE PI N (APEX)

END TAIL

CORNER OF THE PIN

WRAP OF
INSULATED WIRE

No. 30 AWG WIRE

'-r-r--r-----

REFERENCE CORNER
11-4974

Figure B-1

Solderless Wrapped Connection on Wire Wrap Pin

A turn of wire - A turn of wire consists of one complete, single, helical ring of wire wrapped 360 degrees
around a wire wrap pin, intersecting four corners of the pin. Thus, a connection having "n" turns in
contact with the wire wrap pin will intersect the reference corner "n + 1" times (Figure B-2).
A half turn of wire - A half turn of wire contacts three of the four corners of a wire wrap pin (Figure
B-3).
End tail - An end tail is the end of the last turn of wire on the wire wrap pin.

B-1

WIRE CONTACTS ALL FOUR CORNERS,
AND CONTACTS THE REFERENCE
CORNER TWICE.
11-4975

Figure B-2

Full Turn

WIRE CONTACTS
THREE CORNERS
OF PIN

11-4976

Figure B-3

Half Turn

B.3 CONNECTIONS
Turns are counted along the edge of a reference corner (Figure B-1). There should be seven to nine
turns of insulated wire on the wire wrap pin. Each turn should be adjacent to the next turn; one turn
should not be wrapped over another turn. The end tail may extend tangentially away from the wire
wrap pin, but should not extend more than one wire diameter.
If a second level of wire wrap is placed on a wire wrap pin, the bare wire of the second level wrap
should not overlap the first level wrap. The first turn of the insulated wire of the second level wrap
mcY, however, overlap the last turn of the first level wrap (Figure B-4).

The wire used for the jumpers should be good quality wrapping wire. DIGITAL uses the following
specifications for the jumpers installed at the factory:
Conductor
Gauge
30 AWG solid
Material
Silver-coated copper
Diameter
0.0257 + 0.0008 cm or -0.0003 cm (0.0101 + 0.0003 in or - 0.0001 in)

B-2

~_"I----- SECOND

'-.,..,,[..1 - - - - - FIRST

LEVEL

" -4977

Figure B-4

Two Levels of Wire Wrap

Insulation
Material
Vinylindene flouride
Outside Diameter
0.048 ±0.003 cm (0.018 ±0.001 in)
U.L. Style No.
1423
DC Resistance/304.8 m (1000 ft)
113.6 ohms
NOTE
This wire should not be used for solder applications.
Figures B-1 and B-4 show recommended solderless wrapped connections. Figure B-5 illustrates connections that should be avoided.
B.4 PROCEDURE
To install a wire wrap jumper, proceed as follows:
1.

Cut a piece of 30 A W G wire 5.7 cm (2-1/4 in) longer than the distance between the two wire
wrap pins.

Strip 2.7 cm (1-1/16 in) off each end of the wire.

B-3

OVER WRAP
(PILE WRAP)

END TAIL TOO LONG

INSUFFICIENT TURNS

INSUFFICIENT INSULATION

IMPROPER SPACING AND
OVER TAPER END

OVERLAP

BENT WRAP - POST

OPEN WRAP

SPIRAL WRAP
11-5037

Figure B-5

Defective Wire Wraps

B-4

Insert the wire into the wire wrap bit far enough for the insulation to enter the feed slot
(Figure B-6).

Loop the wire through the anchoring notch.

Place the tool on the wire wrap pin and actuate the rotating spindle (bit). This should
produce eight turns of bare wire and one-half to two turns of insulated wire on the wire wrap
pin.

Load the free end of the wire into the wire wrap bit and wrap the other wire wrap pin.

Use an unwrapping tool to remove a wire wrap jumper. A jumper may be snipped out to break the
electrical connection, but when it is desired to reuse the wire wrap pin the remaining wire should be
removed carefully. Pulling the wire off may bend the pin and dent the pin corners. Therefore, it is
recommended than an unwrapping tool be used to remove jumper wire wraps.
Place the tool over the wire wrap pin and insert the end tail of the wrap into the unwrapping tool bit.
Carefully unwrap the wire and discard it. Jumper wires should not be reused.
If it is desired to place a second level wrap on a wire wrap pin, care should be taken not to overlap the
first wrap. If there is insufficient space left on the wire wrap pin for a second level wrap, remove the
first level jumper and install a new one lower on the pin. A wire wrap joint that is installed too high on
the pin should not be forced to a lower level; it should be unwrapped and replaced with a new one at
the lower level.

B-5

' W - - - - STATIONARY

SLEEVE
_~r---- ROTATING SPINDLE
(BIT)
I~

~""'~~--- FEED SLOT

\4----1k+---- STRIPPED WIRE

_ _ _ _ WIRE ANCHORING
NOTCH

TOOL TIP

WIRE INSERTED

WIRE ANCHORED

WRAP-POST
INSERTION

TYPICAL
CONNECTION

11- 5038

Figure B-6

Loading the Wire Wrapping Kit
B-6

DLVll·E AND DLVll·F
ASYNCHRONOUS LINE INTERFACE
USER'S MANUAL
EK·DLVll·0P-OOl

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