DESCRIPTION
The Philips 8XC451 is an I/O expanded single-chip microcontroller fabricated with Philips high-density CMOS technology. Philips epitaxial substrate minimizes latch-up sensitivity. The 8XC451 (includes the 80C451, 87C451 and 83C451) is a functional extension of the 87C51 microcontroller with three additional I/O ports and four I/O control lines for a total of 68 pins. Four control lines associated with port 6 facilitate high-speed asynchronous I/O functions. The 8XC451 includes a 4k × 8 ROM (83C451) EPROM (87C451), a 128 × 8 RAM, 56 I/O, two 16-bit timer/counters, a five source, two priority level, nested interrupt structure, a serial I/O port for either a full duplex UART, I/O expansion, or multi-processor communications, and on-chip oscillator and clock circuits. The 80C451 ROMless version includes all of Idle mode freezes the CPU while allowing the RAM, timers, serial port, and interrupt system to continue functioning. Power-down mode freezes the oscillator, causing all other chip functions to be inoperative while maintaining the RAM contents.
NXP Semiconductors
