鈥?/div>
Extended commercial range of
鈭?0擄C
to +85擄C
Functional Description
The FCT543T octal latched transceiver contains two sets of
eight D-type latches with separate latch enable (LEAB, LEBA)
and output enable (OEAB, OEBA) controls for each set to
permit independent control of inputting and outputting in either
direction of data flow. 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 A or to take data from B, as indicated in the truth
table. With CEAB LOW, a LOW signal on the A-to-B latch
enable (LEAB) input makes the A-to-B latches transparent; a
subsequent LOW-to-HIGH transition of the LEAB signal puts
the A latches in the storage mode and their output no longer
change with the A inputs. With CEAB and OEAB both LOW,
the three-stage B output buffers are active and reflect the data
present at the output of the A latches. Control of data from B
to A is similar, but uses CEAB, LEAB, and OEAB inputs.
The outputs are designed with a power-off disable feature to
allow for live insertion of boards.
Functional Block Diagram
Detail A
D Q
LE
A
0
Q D
LE
B
0
Logic Block Diagram
A
0
CEAB
CEBA
LEAB
LEBA
A
1
A
2
A
3
A
4
A
5
A
6
A
7
OEBA
OEAB
CEBA
CEAB
LEBA
LEAB
B
1
B
2
B
3
B
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
OEAB
OEBA
B
1
B
2
B
3
B
4
B
5
B
6
B
7
Detail A x 7
B
4
B
5
B
6
B
7
Pin Configurations
SOIC/QSOP
Top View
LEBA
OEBA
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
CEAB
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
V
CC
CEBA
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
LEAB
OEAB
Cypress Semiconductor Corporation
鈥?/div>
3901 North First Street
鈥?/div>
San Jose
鈥?CA 95134 鈥?/div>
408-943-2600
May 1994 鈥?Revised March 17, 1997
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