This document describes the features and characteristics of the Harris 82C55A chip. It is a high-performance CMOS programmable I/O device with 24 programmable I/O pins, which can be used with various microprocessors. The chip is compatible with 80C86, 80C88, and other microprocessors, and it offers high speed, low power consumption, and reliability.
The Harris 82C55A is a high-performance CMOS version of the industry-standard 8255A programmable I/O device. Manufactured using a self-aligned silicon gate CMOS process, it offers low operating power and full TTL compatibility over the military temperature range.
The device features 24 programmable I/O pins organized into three major modes of operation: Mode 0 (Basic Input/Output), Mode 1 (Strobed Input/Output), and Mode 2 (Bi-directional Bus). It includes direct bit set/reset capability, enhanced control word read capability, and bus hold circuitry to eliminate the need for pull-up resistors.
| Process Technology | CMOS Programmable Peripheral Interface |
|---|---|
| I/O Pins | 24 Programmable I/O Pins |
| Drive Capability | 2.5mA Drive Capability on All I/O Ports |
The device supports Mode 0 (Basic Input/Output), Mode 1 (Strobed Input/Output), and Mode 2 (Bi-directional Bus).
The device has 24 programmable I/O pins which may be individually programmed in 2 groups of 12.
Yes, its high performance and industry standard configuration make it compatible with the 80C86, 80C88 and other microprocessors.