The TMP82C79M-2 is a programmable keyboard/display interface LSI manufactured by Toshiba Semiconductor and Storage. It is designed to interface microprocessors with keyboard and display devices, significantly reducing the software overhead required for these common input/output functions. This device provides a versatile and efficient method for managing user input and output in a variety of embedded systems and control applications.

Applications:

• Keyboard interface in embedded systems
• Display control in industrial equipment
• Operator panels in CNC machines
• Point-of-sale (POS) terminals
• Instrumentation control panels

Features:

• Fully programmable keyboard and display interface
• Scanned keyboard mode with built-in debounce circuitry
• Encoded keyboard mode
• 8-character display with multiplexed or non-multiplexed operation
• Programmable scan rate
• Interrupt output for key press detection
• FIFO (First-In, First-Out) buffer for keyboard data
• Single +5V power supply

Benefits:

• Reduces microprocessor workload by handling keyboard and display functions
• Simplifies hardware design with integrated keyboard scanning and display multiplexing
• Improves system reliability with built-in debounce circuitry
• Offers flexible configuration options to suit various application requirements
• Low power consumption

Technical Specifications:

The TMP82C79M-2 operates on a single +5V power supply and is typically packaged in a DIP (Dual In-line Package). It supports both scanned and encoded keyboard modes, allowing for connection to a wide range of keyboard types. The display interface can drive up to eight characters, either directly or through multiplexing. The device includes an internal FIFO buffer to store keyboard data, preventing data loss during high-speed typing. The programmable scan rate allows for optimization of display refresh rate and keyboard response time. The interrupt output signals the microprocessor when a key is pressed, enabling efficient interrupt-driven operation.

This chip efficiently manages the interface between a microprocessor and user input/output devices. Its programmability allows developers to tailor its operation to specific application requirements, while its integrated features simplify hardware design and reduce software overhead. The TMP82C79M-2 is a reliable and cost-effective solution for keyboard and display interfacing in a variety of embedded systems.