SN54BCT648 . . . JT OR W PACKAGE

SN74BCT648 . . . DW OR NT PACKAGE

(TOP VIEW)

5

6

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8

9

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11

25

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43

2

1 28

12 13 14 15 16

OE

B1

B2

NC

B3

B4

B5

A1

A2

A3

NC

A4

A5

A6

SN54BCT648...FK PACKAGE

(TOP VIEW)

17 18

27 26

NC − No internal connection

CLKAB

SAB

DIR

A1

A2

A3

A4

A5

A6

A7

A8

GND

CLKBA

SBA

OE

B1

B2

B3

B4

B5

B6

B7

B8

1

2

3

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SN54BCT648, SN74BCT648

OCTAL BUS TRANSCEIVERS AND REGISTERS

WITH 3STATE OUTPUTS

SCBS050B − MAY 1990 − REVISED APRIL 1994

Copyright

1

POST OFFICE BOX 655303

POST OFFICE BOX 1443

Small-Outline (DW) Packages, Ceramic

Chip Carriers (FK) and Flatpacks (W), and

Standard Plastic and Ceramic 300-mil DIPS

(JT, NT)

description

These devices consist of bus transceiver circuits

with 3-state outputs, D-type flip-flops, and control

circuitry arranged for multiplexed transmission of

data directly from the input bus or from the internal

registers. Data on the A or B bus will be clocked

into the registers on the low-to-high transition of

the appropriate clock (CLKAB or CLKBA) input.

Figure 1 illustrates the four fundamental bus-

management functions that can be performed with

the

′BCT648.

Output-enable (OE) and direction-control (DIR)

inputs are provided to control the transceiver

functions. In the transceiver mode, data present at

the high-impedance port may be stored in either

register or in both. The select control (SAB and

SBA)

can

multiplex

stored

and

real-time

(transparent mode) data. The direction control

determines which bus will receive data when OE

is active (low). In the isolation mode (OE high), A

data may be stored in one register and/or B data

may be stored in the other register.

When an output function is disabled, the input function is still enabled and may be used to store and transmit

data. Only one of the two buses, A or B, may be driven at a time.

The SN54BCT648 is characterized for operation over the full military temperature range of −55

°C to 125°C. The

SN74BCT648 is characterized for operation from 0

°C to 70°C.

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.