SN54BCT8244A, SN74BCT8244A

SCAN TEST DEVICES

WITH OCTAL BUFFERS

SCBS042E – FEBRUARY 1990 – REVISED JULY 1996

2

POST OFFICE BOX 655303

description (continued)

Four dedicated test terminals control the operation of the test circuitry: test data input (TDI), test data output

(TDO), test mode select (TMS), and test clock (TCK). Additionally, the test circuitry performs other testing

functions such as parallel-signature analysis (PSA) on data inputs and pseudo-random pattern generation

(PRPG) from data outputs. All testing and scan operations are synchronized to the TAP interface.

The SN54BCT8244A is characterized for operation over the full military temperature range of –55

°C to 125°C.

The SN74BCT8244A is characterized for operation from 0

°C to 70°C.

FUNCTION TABLE

(normal mode, each buffer)

INPUTS

OUTPUT

OE

A

Y

H

X

Z

L

LL

L

H

H

SCAN

’BCT8244A

23

1A1

1Y1

2

TDI

14

TDI

TCK-IN

EN1

1

22

1A2

1Y2

3

TMS

12

TMS

13

TCK

EN2

24

TCK-OUT

21

1A3

1Y3

4

20

1A4

1Y4

5

19

2A1

2Y1

7

17

2A2

2Y2

8

16

2A3

2Y3

9

15

2A4

2Y4

10

2OE

1OE

Φ

1

2

TDO

11

TDO

† This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.

Pin numbers shown are for the DW, JT, and NT packages.