W78E54 8-bit microcontroller introduction

The W78E54B is a wide frequency range, low power 8-bit microcontroller. Its instruction set is fully compatible with the standard 8051 instruction set. W78E54B contains 16K bytes of Flash EPROM; 256 bytes of RAM; 4 8-bit bidirectional, bit-addressable I/O ports; an additional 4-bit I/O port P4; 3 16-bit timer/counters; A hardware watchdog timer and a serial port. These peripherals are all supported by an interrupt system with 7 interrupt sources and 2 interrupt capabilities. To facilitate user programming and verification, the Flash EPROM included in the W78E54B allows both electrical and electronic reads and writes. Once the code is determined, the user can protect the code.

W78E54B has two kinds of power-saving modes, idle mode and power-down mode. Both modes can be controlled by software. In idle mode, the processor clock is turned off but the peripherals continue to operate. The crystal oscillator stops operating in power-down mode to minimize power consumption. The external clock can be turned off at any time and state without affecting the processor operation.

2. Features · Fully static design CMOS 8-bit microprocessor · Wide voltage range: 4.5V - 5.5V
256-byte on-chip scratch RAM
16K byte on-chip Flash EPROM
64KB program memory address space 64KB data memory address space 4 8-bit bidirectional I/O ports 1 additional 4-bit addressable I/O port with 2 interrupts added
(limited to PLCC/PQFP 44-core package)
· Three 16-bit timer/counters · One full-duplex serial port (UART)
· Watchdog timer · 8 interrupt sources, 2-level interrupt capability · Reduced EMI mode · Built-in power management · Code protection mechanism · Package:
- DIP40: W78E54B-40
- PLCC44: W78E54BP-40
- PQFP44: W78E54BF-40
- Lead-Free Package DIP40: W78E054B40DL
- Lead-free package PLCC44: W78E054B40PL
- Lead-Free Package PQFP44: W78E054B40FL