GENERAL DESCRIPTION

The W78E54B is an 8-bit microcontroller which can accommodate a wider frequency range with low power consumption. The instruction set for the W78E54B is fully compatible with the standard 8051. The W78E54B contains an 16K bytes Flash EPROM; a 256 bytes RAM; four 8-bit bi-directional and bit addressable I/O ports; an additional 4-bit I/O port P4; three 16-bit timer/counters; a hardware watchdog timer and a serial port. These peripherals are supported by eight sources two-level interrupt capability. To facilitate programming and verification, the Flash EPROM inside the W78E54B allows the program memory to be programmed and read electronically. Once the code is confirmed, the user can protect the code for security.

FEATURES

? Fully static design 8-bit CMOS microcontroller

? Wide supply voltage of 4.5V to 5.5V

? 256 bytes of on-chip scratchpad RAM

? 16 KB electrically erasable/programmable Flash EPROM

? 64 KB program memory address space

? 64 KB data memory address space

? Four 8-bit bi-directional ports

? One extra 4-bit bit-addressable I/O port, additional INT2 / INT3 (available on 44-pin PLCC/QFP package)

? Three 16-bit timer/counters

? One full duplex serial port(UART)

? Watchdog Timer

? Eight sources, two-level interrupt capability

? EMI reduction mode

? Built-in power management

? Code protection mechanism

? Packages:

? DIP 40: W78E54B-24/40

? PLCC 44: W78E54BP-24/40

? PQFP 44: W78E54BF-24/40