The document provides information about the W78C438BP-24 supplier.
The W78C438B is an 8‑bit CMOS microcontroller offering up to 40 MHz operation, 256‑byte on‑chip RAM, and flexible external memory options. It is compatible with the W78C32 family while adding extra I/O ports, address ports, and external interrupts.
The handbook covers general description, pin configurations, detailed pin descriptions, functional registers, memory mapping, package dimensions for PLCC and QFP packages, and example code snippets for using the EPMA register and external interrupts.
| 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 memory‑mapped chip select |
| I/O ports | Five 8‑bit bidirectional ports + one 8‑bit parallel port |
| Timers | Three 16‑bit timer/counters |
| External interrupts | Four |
| Serial interface | One full‑duplex serial channel |
| Package options | 84‑pin PLCC or 100‑pin PQFP |
The device can operate up to 40 MHz.
It has five 8‑bit bidirectional I/O ports and one additional 8‑bit parallel I/O port.
The microcontroller can use either a 64 KB program/1 MB data memory space or memory‑mapped chip‑select pins.
Four external interrupts are provided.