SN54LVT16646, SN74LVT16646

3.3-V ABT 16-BIT BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SCBS149C – JULY 1994 – REVISED JULY 1995

2

POST OFFICE BOX 655303

description (continued)

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.

Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.

resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

The SN74LVT16646 is available in TI’s shrink small-outline (DL) and thin shrink small-outline (DGG) packages,

which provide twice the I/O pin count and functionality of standard small-outline packages in the same

printed-circuit-board area.

The SN54LVT16646 is characterized for operation over the full military temperature range of – 55

°C to 125°C.

The SN74LVT16646 is characterized for operation from – 40

°C to 85°C.

FUNCTION TABLE

INPUTS

DATA I/Os

OPERATION OR FUNCTION

OE

DIR

CLKAB

CLKBA

SAB

SBA

A1 THRU A8

B1 THRU B8

OPERATION OR FUNCTION

X

X

↑

X

X

X

Input

Unspecified†

Store A, B unspecified†

X

XX

↑

X

X

Unspecified†

Input

Store B, A unspecified†

H

X

↑

↑

X

X

Input

Input

Store A and B data

H

X

H or L

H or L

X

X

Input disabled

Input disabled

Isolation, hold storage

L

L

X

X

X

L

Output

Input

Real-time B data to A bus

L

L

X

H or L

X

H

Output

Input

Stored B data to A bus

L

H

X

X

L

X

Input

Output

Real-time A data to B bus

L

H

H or L

X

H

X

Input

Output

Stored A data to B bus

† The data output functions may be enabled or disabled by various signals at OE and DIR. Data input functions are always enabled; i.e., data at

the bus pins will be stored on every low-to-high transition of the clock inputs.