The UPD8279C-5 is a programmable keyboard and display controller designed by NEC. It serves as an interface between a microprocessor and input/output devices like keyboards and displays, handling scanning, debouncing, encoding, and display refreshing. This reduces the computational burden on the CPU and streamlines overall system design.

Applications:

• Computer keyboards
• LED and LCD displays
• Embedded systems
• Industrial control panels

Features:

• Scanned keyboard interface with built-in debouncing and FIFO buffer
• Scanned display interface with multiplexing capabilities
• Supports up to 8-character displays
• Capable of handling up to 16-key keyboards
• Programmable modes for versatile keyboard and display control
• Generates interrupt signals for keyboard data availability

Benefits:

• Simplified Interface: The UPD8279C-5 eases the process of interfacing keyboards and displays by managing scanning, debouncing, encoding, and refreshing automatically.
• Reduced CPU Load: By independently managing I/O, the CPU is free to perform other essential tasks.
• Increased Efficiency: The FIFO buffer and interrupt handling mechanisms ensure reliable and efficient data transfer.
• Versatile Adaptability: Programmable modes provide flexibility to accommodate various keyboard and display types.

Technical Specifications:

The UPD8279C-5 is typically packaged in a 40-pin DIP. It operates with a 5V power supply. It supports different keyboard modes, including encoded and decoded scan modes. Display modes include left entry and right entry. The FIFO buffer stores up to eight keystrokes to prevent data loss during rapid typing. External drivers are usually required to drive the display segments.