Harman Kardon AVR525 Service Manual page 139

AVR525
8-bit compatible shift / store register
BU4094BC / BU4094BCF / BU4094BCFV
The BU4094BC, BU4094BCF, and BU4094BCFV are shift / store registers, each consisting of an 8-bit register and
an 8-bit latch.
As the data in the shift register can be latched by an asynchronous strobe input, it is possible to hold the output in
the data transfer mode.
The tri-state parallel output can be connected directly with an 8-bit bus line.
These registers are suitable for in-line / parallel data conversion, data receivers and other similar applications.
•
Logic circuit diagram
SERIAL
IN 8-STAGE
SHIFT REGISTER
CLOCK
STROBE
LATCHES
OUTPUT
ENABLE OUTPUTS
Q
1
PARALLEL OUTPUTS
•
Truth table
OUTPUT
CLOCK STROBE
ENABLE
H H
H H
H L
L X
H X
L X
NC: No Change Z: High Impedance
Q
S
Q'
S
SERIAL
OUTPUT
8-BIT
3-STATE
Q
8
Parallel output
SERIAL IN
Q
1
L L
H H
X NC
X Z
X NC
X Z
X: Irrelevant
•
Block diagram
1
STROBE
SERIAL
2
IN
3
CLOCK
4
Q
1
5
Q
2
6
Q
3
7
Q
4
8
V
SS
Serial output
Q Q Q'
n S S
Q Q NC
n-1 7
Q Q NC
n-1 7
NC Q NC
7
Z Q NC
7
NC NC Q
S
Z NC Q
S
139
harman/kardon
16
V
DD
OUTPUT
15
ENABLE
14
Q
5
13
Q
6
12
Q
7
11
Q
8
10
Q'
S
9 Q
S