The W78C54 8-bit microcontroller is a derivative of the W78C52 microcontroller family that provides extended internal ROM. The chip has 16K bytes of mask ROM and 256 bytes of RAM. This device provides an enhanced architecture that makes it more powerful and suitable for a variety of general control systems applications. It provides on-chip 16KB mask ROM to accommodate large program codes, 256-bytes of non-volatile on-chip RAM, four 8-bit I/O ports, one 4-bit I/O port, three 16-bit timer/counters, eight sources with two-level interrupt structures, and on-chip oscillator clock circuits.
The W78C54 is an 8‑bit microcontroller from Winbond that adds 16 KB of on‑chip mask ROM and 256 bytes of RAM to the W78C52 family. It offers a range of peripherals including four 8‑bit I/O ports, an extra 4‑bit port, three 16‑bit timers, and two‑level interrupt handling, making it suitable for general control applications.
The manual covers features, package options, pin‑out tables, functional block diagrams, power‑management modes (idle and power‑down), special function registers, and detailed programming examples. It also includes mechanical dimensions for the various DIP, PLCC, and QFP packages.
| Operating frequency | DC to 40 MHz |
|---|---|
| On‑chip ROM | 16 KB mask ROM |
| On‑chip RAM | 256 bytes scratch‑pad RAM |
| External program memory address space | 64 KB |
| External data memory address space | 64 KB |
| I/O ports (8‑bit) | Four bit‑addressable ports |
| Additional I/O port | One 4‑bit bit‑addressable port (P4) |
| Timers | Three 16‑bit timer/counters |
| Interrupt sources | Eight sources, two priority levels |
| Power‑saving modes | Idle mode and Power‑down mode |
| EMI reduction | Low EMI emission mode |
The device operates from DC up to 40 MHz.
It contains 16 KB of on‑chip mask ROM.
The microcontroller supports an idle mode and a power‑down mode.
It has four 8‑bit bit‑addressable I/O ports plus an extra 4‑bit port (P4).