GENERAL DESCRIPTION

The ISSI IS80C51 and IS80C31 are high-performance microcontrollers fabricated using high-density CMOS technology. The CMOS IS80C51/31 is functionally compatible with the industry standard 80C51 microcontrollers.

The IS80C51/31 is designed with 4K x 8 ROM (IS80C51 only); 128 x 8 RAM; 32 programmable I/O lines; a serial I/O port for either multiprocessor communications, I/O expansion or full duplex UART; two 16-bit timer/counters; a six-source, two-priority-level, nested interrupt structure; and an on-chip oscillator and clock circuit. The IS80C51/31 can be expanded using standard TTL compatible memory.

FEATURES

• 80C51 based architecture

• 4K x 8 ROM (IS80C51 only)

• 128 x 8 RAM

• Two 16-bit Timer/Counters

• Full duplex serial channel

• Boolean processor

• Four 8-bit I/O ports, 32 I/O lines

• Memory addressing capability

   – 64K ROM and 64K RAM

• Power save modes:

   – Idle and power-down

• Six interrupt sources

• Most instructions execute in 0.3 µs

• CMOS and TTL compatible

• Maximum speed: 40 MHz @ Vcc = 5V

• Industrial temperature available

• Packages available:

   – 40-pin DIP

   – 44-pin PLCC

   – 44-pin PQFP