DESCRIPTION

The Philips microcontrollers described in this data sheet are

high-performance static 80C51 designs incorporating Philips’

high-density CMOS technology with operation from 2.7 V to 5.5 V.

They support both 6-clock and 12-clock operation.

The 8xC31X2/51X2 and 8xC32X2/52X2/54X2/58X2 contain

128 byte RAM and 256 byte 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, and on-chip

oscillator and clock circuits.

In addition, the devices are low power static designs which offer 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. Since the design is static, the clock can be stopped

without loss of user data. Then the execution can be resumed from

the point the clock was stopped.