74670
The 74670 is a tri-state 4x4 register file 74-series logic IC, often used to reduce chip count when having many registers in the implementaion.
74670 Pinout
.--__--.
D1 -|01 16|- VCC
D2 -|02 15|- D0
D3 -|03 14|- Write A0
Read A1 -|04 13|- Write A1
Read A0 -|05 12|- /WE
Q3 -|06 11|- /OE
Q2 -|07 10|- Q0
GND -|08 09|- Q1
'------'
- D0-D3 : data input lines
- Q0-Q3 : data output lines
- Write A0-A1 : write register selection
- Read A0-A1 : read register selection
- /WE : copy the current content of D0-D3 to the selected register when this pin is low
- /OE : output the current content of the selected register when this pin is low, otherwise high-impedance
- VCC, GND : power supply