This document describes the features of MSM82C55A-2RS/GS/VJS, which is a programmable universal I/O interface device based on 3m silicon gate CMOS technology. It has high speed and low power consumption, and is suitable as an I/O port for the 8-bit parallel processing MSM80C85AH CPU. The device has 24-bit I/O pins, equivalent to three 8-bit I/O ports, and all inputs/outputs are TTL interface compatible.
The MSM82C55A-2 series is a programmable universal I/O interface device built with 3‑µm silicon‑gate CMOS technology. It provides 24‑bit I/O pins (three 8‑bit ports) that are TTL‑compatible and can operate from a single 3 V to 6 V supply.
Key features include high‑speed operation, low power consumption, full static operation, bidirectional bus capability on Port A, and compatibility with the classic 8255A‑5 peripheral. The device is offered in several plastic packages such as 40‑pin DIP, 44‑pin QFP and 44‑pin QFP‑2K, with detailed electrical characteristics and timing diagrams provided for designers.
| Supply Voltage | 3 V to 6 V |
|---|---|
| Operating Temperature | -40 °C to 85 °C |
| Input Low Voltage (VIL) | 0.3 V to 0.8 V |
| Input High Voltage (VIH) | 2.2 V to VEE+0.3 V |
The device operates from a single supply of 3 V to 6 V.
It provides 24‑bit I/O pins, equivalent to three 8‑bit ports.