UPD750402A Overview
VECTOR INTERRUPT REQUEST FOR EDGE DETECT EXTERNAL TEST FOR EDGE DETECT 4-BIT PORT (PORT 0) 2-BIT PORT (PORT 1) SYSTEM RESET SERIAL CLOCK SERIAL DATA SYSTEM CLOCK PROGRAM SUPPLY VOLTAGE, (NORMAL OPERATION : GND) INPUT/OUTPUT P01 - P02 : 4-BIT PORT (PORT 0) P20 - P23.