HD74HC670 Datasheet, PDF (3/10 Pages) Hitachi Semiconductor – 4-by-4 Register File (with 3-state outputs)

Pin Arrangement
HD74HC670
D2 1
Data D3 2
D4 3
RB 4
Read
select
RA 5
Q4 6
Outputs
Q3 7
GND 8
D3
D2
D₁
D4
WA
RB
WB
RA
CW
Q4
CR
Q3 _Q2 Q1
16 V_CC
15 ^Data
D₁
14 WA
13 WB
Write
select
12 Write
Enable
11 Read
10 Q1
9 Q2
Outputs
Logic Diagram
(Top view)
To other three bits
Data
WA
WB
GW
D
G
D
Q
G
D
Q
G
Q
D
G
Q
VCC
Q
RA
GR
RB
3