Harman Kardon AVR220 Service Manual page 76

AVR220
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
CLOCK
STROBE
OUTPUT
ENABLE
Q
•
Truth table
OUTPUT
CLOCK
ENABLE
H
H
H
L
H
L
NC: No Change Z: High Impedance
8-STAGE Q
S
SHIFT REGISTER
Q'
S
SERIAL
OUTPUT
8-BIT
LATCHES
3-STATE
OUTPUTS
Q
1 8
PARALLEL OUTPUTS
STROBE SERIAL IN
H L
H H
L X
X X
X X
X X
X: Irrelevant
•
Block diagram
STROBE
Parallel output Serial output
Q Q Q
1 n S
L Q Q
n-1 7
H Q Q
n-1 7
NC NC Q
7
Z Z Q
7
NC NC NC
Z Z NC
76
1
SERIAL
2
IN
3
CLOCK
4
Q
1
5
Q
2
6
Q
3
7
Q
4
8
V
SS
Q'
S
NC
NC
NC
NC
Q
S
Q
S
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