74abt16543bb NXP Semiconductors, 74abt16543bb Datasheet - Page 6

• Manufacturer Part Number: 74abt16543bb
• Description: 74abt16543 16-bit Latched Transceiver With Dual Enable 3-state
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7. Functional description
9397 750 15046
Product data sheet
7.1 Function table
7.2 Description
Table 4:
[1]
The 74ABT16543 contains two sets of eight D-type latches, with separate control pins for
each set. Using data flow from A to B as an example, when the A-to-B enable (nEAB)
input and the A-to-B latch enable (nLEAB) input are LOW the A-to-B path is transparent.
A subsequent LOW-to-HIGH transition of the nLEAB signal puts the A data into the
latches where it is stored and the B outputs no longer change with the A inputs. With
nEAB and nOEAB both LOW, the 3-state B output buffers are active and display the data
present at the outputs of the A latches.
Control of data flow from B to A is similar, but using the nEBA, nLEBA, and nOEBA inputs.
Input
nOEAB or
nOEBA
H
X
L
L
L
L
L
L
L
H = HIGH voltage level;
h = HIGH voltage level one set-up time prior to the LOW-to-HIGH transition of nLEAB, nLEBA, nEAB or
nEBA;
L = LOW voltage level;
l = LOW voltage level one set-up time prior to the LOW-to-HIGH transition of nLEAB, nLEBA, nEAB or
nEBA;
X = don t care;
Z = high-impedance off state;
NC= no change.
= LOW-to-HIGH transition;
Function table
nEAB or
nEBA
X
H
L
L
L
L
L
Rev. 04 — 26 May 2005
[1]
nLEAB or
nLEBA
X
X
L
L
L
L
H
16-bit latched transceiver with dual enable; 3-state
nAx or nBx
X
X
h
I
h
I
H
L
X
Output
nBx or nAx
Z
Z
Z
Z
H
L
H
L
NC
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
74ABT16543
Status
disabled
disabled
disabled + latch
disabled + latch
latch + display
latch + display
transparent
transparent
hold
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