IN80C51N

The IN80C51N is a high-performance microcontroller fabricated with high-density CMOS technology.

The IN80C51N contains a 4k x 8 ROM , a 128 x 8 RAM , 32 I/O lines, two 16-bit counter/timers, a five-source, two-priority level nested interrupt structure, a serial I/O port for either multi-processor communications, I/O expansion or full duplex UART, and onchip oscillator and clock circuits.

The IN80C51N has two software selectable modes of power reduction  idle mode and power-down mode. The idle mode freezes the CPU while allowing the RAM, timers, serial port, and interrupt system to continue functioning. The power-down mode saves the RAM contents but freezes the oscillator, causing all other chip functions to be inoperative.