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2

Connection Diagram

Pin Descriptions

Functional Description

The LVT16543 and LVTH16543 contain two sets of D-type

latches, with separate input and output controls for each.

For data flow from A to B, for example, the A to B Enable

(CEAB) input must be LOW in order to enter data from the

A Port or take data from the B Port as indicated in the Data

I/ O Control Table. With CEAB LOW, a low signal on

(LEAB) input makes the A to B latches transparent; a sub-

sequent LOW-to-HIGH transition of the LEAB line puts the

A latches in the storage mode and their outputs no longer

change with the A inputs. With CEAB and OEAB both

LOW, the B output buffers are active and reflect the data

present on the output of the A latches. Control of data flow

from B to A is similar, but using the CEBA, LEBA and

OEBA. Each byte has separate control inputs, allowing the

device to be used as two 8-bit transceivers or as one 16-bit

transceiver.

Data I/O Control Table

H

= HIGH Voltage Level

L

= LOW Voltage Level

X

= Immaterial

Pin

Names

Description

A-to-B Output Enable Input (Active LOW)

B-to-A Output Enable Input (Active LOW)

A-to-B Enable Input (Active LOW)

B-to-A Enable Input (Active LOW)

A-to-B Latch Enable Input (Active LOW)

B-to-A Latch Enable Input (Active LOW)

A-to-B Data Inputs or

B-to-A 3-STATE Outputs

B-to-A Data Inputs or

A-to-B 3-STATE Outputs

Inputs

Latch Status

(Byte n)

Output

Buffers

(Byte n)

H

X

X

Latched

High Z

XH

X

Latched

—

L

L

X

Transparent

—

XX

H

—

High Z

LX

L

—

Driving