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Publication Release Date: April, 1999

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Revision A0


The W78C516 is a derivative of the W78C52 microcontroller family that provides extended internal

ROM. The chip has 64K 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 applications for general control systems. It provides on-chip 64KB 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.


DC to 40 MHz  extensive operating frequency

256-byte on-chip scratch pad RAM

64K-byte on-chip mask ROM

64K-byte address space for external Program Memory

64K-byte address space for external Data Memory

Three 16-bit timer/counters

Four 8-bit bit-addressable I/O ports

One extra 4-bit bit-addressable I/O port (available on 44-pin PLCC/QFP package)

Six-source, two priority-level interrupts

Built-in programmable power-saving modes - Idle mode & Power-down mode


 DIP 40: W78C516-24/40

 PLCC 44: W78C516P-24/40


 QFP 44: W78C516F-24/40