W78C32B datasheet
The W78C32B is an 8‑bit CMOS microcontroller featuring 256 bytes of on‑chip RAM, four 8‑bit bidirectional I/O ports, three 16‑bit timer/counters and a full‑duplex serial port. It supports ROM‑less operation, two software‑selectable power‑saving modes and operates up to 40 MHz.
The document provides full pin configurations, electrical characteristics, absolute maximum ratings, timing diagrams and package dimensions for DIP‑40, PLCC‑44 and QFP‑44 variants.
| Operating Voltage | 4.5 V – 5.5 V |
|---|---|
| No‑load Current | 30 mA |
| Power‑down Current | 50 pA |
| Maximum Clock Frequency | 40 MHz |
| Program Memory | 64 KB |
| Data Memory | 64 KB |
| On‑chip RAM | 256 bytes |
| I/O Ports | Four 8‑bit bidirectional ports |
| Package Types | DIP‑40, PLCC‑44, QFP‑44 |
It has two software‑selectable modes: idle mode, which stops the processor clock while keeping peripherals active, and power‑down mode, which stops the crystal oscillator for minimum power consumption.
The device provides four 8‑bit bidirectional I/O ports.
The microcontroller can operate up to 40 MHz.
P3.0 is the serial receive data (RXD) pin, and P3.4 is the serial transmit data (TXD) pin.