
HD74AC670
2
Logic Symbol
14
11
12
15
1
2
3
10
9
7
6
13
5
4
WE
D
1
D
2
D
3
D
4
OE
O
1
O
2
O
3
O
4
WA
0
WA
1
RA
0
RA
0
V
CC
=Pin 16
GND=Pin 8
Pin Names
D
1
to D
4
WA
0
, WA
1
WE
RA
0
, RA
1
OE
O
1
to O
4
Data Inputs
Write Address Inputs
Write Enable Input (Active Low)
Read Address Inputs
3-State Output Enable Input (Active Low)
Data Outputs
Write Function Table
Write Inputs
WE
WA
1
L
WA
0
L
D Inputs to
L
Word 0
L
L
H
Word 1
L
H
L
Word 2
L
H
H
Word 3
H
H :
L
X :
X
X
None (hold)
High Voltage Level
Low Voltage Level
Immaterial
: