74actq543 Fairchild Semiconductor, 74actq543 Datasheet - Page 2

• Manufacturer Part Number: 74actq543
• Description: Quiet Series ?ctal Registered Transceiver With 3-state Outputs
• Manufacturer: Fairchild Semiconductor

www.fairchildsemi.com
Logic Symbols
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
IEEE/IEC
2
Functional Description
The ACQ/ACTQ543 contains two sets of eight D-type
latches, with separate input and output controls for each
set. 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
Data I/O Control 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 outputs no longer change with the A inputs. With
CEAB and OEAB both LOW, the 3-STATE B output buffers
are active and reflect the data present at the output of the A
latches. Control of data flow from B to A is similar, but using
the CEBA, LEBA and OEBA inputs
Data I/O Control Table
H
L
X
A-to-B data flow shown; B-to-A flow control is the same, except using
CEBA, LEBA and OEBA
CEAB
H
X
X
L
L
LOW Voltage Level
HIGH Voltage Level
Immaterial
0
–A
Inputs
LEAB
7
H
X
X
X
L
or take data from B
OEAB
H
X
X
X
L
Latch Status
Transparent
Latched
Latched
0
—
—
–B
7
, as indicated in the
Output Buffers
Driving
High Z
High Z
—
—