W78C438C is a high-performance single-chip CMOS 8-bit microcontroller that is a derivative of the W78C58 microcontroller family. It is functionally compatible with the W78C32, except that it provides either a 64 KB program/1 MB data memory address or memory-mapped chip select logic, five general I/O ports, and four external interrupts.
The W78C438C is a high‑performance 8‑bit CMOS microcontroller from Winbond, extending the W78C58 family with larger memory options and additional I/O ports. This manual describes its architecture, pin assignments, and programming model.
Key features include up to 40 MHz operation, 256‑byte on‑chip RAM, flexible memory mapping (64 KB program/1 MB data or chip‑select mode), five bidirectional I/O ports, a parallel port, three 16‑bit timers, four external interrupts, and a full‑duplex serial channel. Package options are 84‑pin PLCC and 100‑pin PQFP.
| Microcontroller type | 8-bit CMOS |
|---|---|
| Design | Fully static |
| Maximum operating frequency | 40 MHz |
| On‑chip RAM | 256 bytes scratchpad |
| External memory options | 64 KB program / 1 MB data or 4 chip‑select pins |
| I/O ports | Five 8‑bit bidirectional ports + one parallel port |
| Timers/Counters | Three 16‑bit |
| External interrupts | Four |
| Serial interface | One full‑duplex channel |
The microcontroller can operate up to 40 MHz.
It provides five 8‑bit bidirectional I/O ports plus an additional parallel port.
It can use either a 64 KB program/1 MB data memory space or a set of four memory‑mapped chip‑select pins.