121101

The P87C51SBPN is a 8-bit high-performance Static Design Microcontroller with Philips high-density CMOS technology with operation from 2.7 to 5.5V. The 8xC51 contain a 128bytes RAM and 256bytes RAM respectively, 32 I/O lines, three 16-bit counter/timers, a six-source, four-priority level nested interrupt structure, a serial I/O port for either multi-processor communications, I/O expansion or full duplex UART, on-chip oscillator and clock circuits. In addition, the device is a low power static design which offers a wide range of operating frequencies down to zero. Two software selectable modes of power reduction-idle mode and power-down mode are available. 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.