MC74HC597A
http://onsemi.com
7
FUNCTION TABLE
Operation
Inputs Resulting Function
Reset
Serial Shift/
Parallel Load
Latch
Clock
Shift
Clock
Serial
Input
S
A
Parallel
Inputs
A−H
Latch
Contents
Shift
Register
Contents
Output
Q
H
Reset shift register L X L, H, X X X U L L
Reset shift register; load
parallel data into data latch
L X X X a−h a−h L L
Load parallel data into data
latch
H H L,H, X a−h a−h U U
Transfer latch contents to
shift register
H L L, H, X X X U LR
N
→ SR
N
LR
H
Contents of data latch and
shift register are
unchanged
H H L, H, L,H, X X U U U
Load parallel data into data
latch and shift register
H L X X a−h a−h a−h h
Shift serial data into shift
register
H H X D X * SR
A
= D;
SR
N
→ SR
N+1
SR
G
→ SR
H
Load parallel data into data
latch and shift serial data
into shift register
H H D a−h a−h SR
A
= D;
SR
N
→ SR
N+1
SR
G
→ SR
H
LR = latch register contents a−h = data at parallel data inputs A−H U = remains unchanged
SR = shift register contents D = data (L, H) at serial data input S
A
X = don’t care
* = depends on latch clock input
