W78E54

8-BIT MICROCONTROLLER

Publication Release Date: November 1997

- 1 -

Revision A2

GENERAL DESCRIPTION

The W78E54 is an 8-bit microcontroller that is functionally compatible with the W78C54, except that

the mask ROM is replaced by a flash EEPROM with a size of 16 KB. To facilitate programming and

verification, the flash EEPROM inside the W78E54 allows the program memory to be programmed

and read electronically. Once the code is confirmed, the user can protect the code for security.

The W78E54 microcontroller supplies a wider frequency range than most 8-bit microcontrollers on the

market. It is functionally compatible with the industry-standard 80C52 microcontroller series, except

INT3 ).

The W78E54 contains four 8-bit bidirectional and bit-addressable I/O ports, three 16-bit

timer/counters, and a serial port. These peripherals are supported by a eight-source, two-level

interrupt capability. There are 256 bytes of RAM and an 16 KB flash EEPROM for application

programs.

The W78E54 microcontroller has two power reduction modes, idle mode and power-down mode, both

of which are software selectable. The idle mode turns off the processor clock but allows for continued

peripheral operation. The power-down mode stops the crystal oscillator for minimum power

consumption. The external clock can be stopped at any time and in any state without affecting the

processor.

FEATURES

(available on 44-pin PLCC/QFP package)

− DIP 40: W78E54-16/24/40

− PLCC 44: W78E54P-16/24/40

− QFP 44: W78E54F-16/24/40

− TQFP 44: W78E54M-16/24/40