Datasheet

2
Functional Diagram
9
6
7
10
Q0
Q1
Q2
Q3
4
11
15
1
3
D0
D2
WE
RE
514 13
RA1
RA0
WA0
WA1
12
2
D1
D3
WRITE MODE SELECT TABLE
OPERATING
MODE
INPUTS INTERNAL
LATCHES
(NOTE 1)WE D
N
Write Data L L L
LHH
Data Latched H X No Change
NOTE:
1. The Write Address (WA0 and WA1) to the “internal latches” must
be stable while WE is LOW for conventional operation.
READ MODE SELECT TABLE
OPERATING
MODE
INPUTS
OUTPUT
Q
N
RE
INTERNAL
LATCHES
(NOTE 2)
Read L L L
LHH
Disabled H X (Z)
NOTE:
2. The selection of the “internal latches” by Read Address (RA0 and
RA1) are not constrained by WE or RE operation.
H = High Voltage Level
L = Low Voltage Level
X= Don’t Care
Z = High Impedance “Off” State
CD54HC670, CD74HC670, CD74HCT670CD54HC670, CD74HC670, CD74HCT670