SN74ACT8994

DIGITAL BUS MONITOR

IEEE STD 1149.1 (JTAG) SCAN-CONTROLLED LOGIC/SIGNATURE ANALYZER

SCAS196E – JULY 1990 – REVISED DECEMBER 1996

1

POST OFFICE BOX 655303

Family of Testability Products

1149.1-1990 (JTAG) Test Access Port and

Boundary-Scan Architecture

Random-Access Memory (RAM) to Store

the States of a Digital Bus

Test Clock or System Clock(s)

Qualification Module for Real-Time System

Test

Monitoring and Test Operations

of Data Inputs With User-Definable

Feedback

Operations

of Parallel Data Paths Greater Than 16 Bits

in Width

Memory and Register File Read/Write

Operations

Reduces Power Dissipation

CMOS) 1-

µm Process

32 1 28 27

12 13 14 15 16 17 18

5

6

7

8

9

10

11

25

24

23

22

21

20

19

D8

D9

D10

D11

D12

D13

D14

D1

D0

CLK1

CLK2

CLK3

TMS

TCK

426

FN PACKAGE

(TOP VIEW)

description

The SN74ACT8994 digital bus monitor (DBM) is a member of the Texas Instruments SCOPE

™ testability

integrated-circuit family. This family of components supports IEEE Standard 1149.1-1990 (JTAG) boundary

scan to facilitate testing of complex circuit-board assemblies. The DBM is a boundary-scannable device

designed to monitor and/or store the values of a digital bus up to 16 bits in width. It resides in parallel with the

bus being monitored.

Data at the D-input pins can be stored in a scannable random-access memory (RAM). Up to 1024 words of

16 bits can be stored. A parallel-signature analysis (PSA) can be performed on the data or on the contents of

memory. The PSA operations use a linear-feedback shift-register technique to compress data into a signature.

The user can configure the device to mask any combination of data inputs and control the feedback used during

PSA operations.

Copyright

© 1996, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

SCOPE and EPIC are trademarks of Texas Instruments Incorporated.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

On products compliant to MIL-PRF-38535, all parameters are tested

unless otherwise noted. On all other products, production

processing does not necessarily include testing of all parameters.