The UPD8279C-2 is a programmable keyboard and display controller manufactured by NEC. It interfaces a microprocessor to a keyboard for data entry and to a display for output, managing scanning, debouncing, encoding, and display refreshing tasks. This reduces the workload on the CPU and simplifies system design.

Applications:

• Keyboard interfaces for computers
• Display interfaces for embedded systems
• Industrial control panels
• Point-of-sale terminals

Features:

• Scanned keyboard interface with debounce and FIFO storage
• Scanned display interface with multiplexing capabilities
• 8-character display capability
• 16-key keyboard input capability
• Programmable modes for keyboard and display operations
• Interrupt output for keyboard data availability

Benefits:

• Simplified keyboard and display interfacing: The UPD8279C-2 handles the complex tasks of scanning, debouncing, encoding, and refreshing, reducing the need for complex software routines.
• Reduced CPU overhead: By managing the keyboard and display independently, the controller frees up the CPU for other tasks.
• Improved system efficiency: The FIFO storage and interrupt output ensure efficient data transfer between the keyboard/display and the CPU.
• Flexibility: Programmable modes allow the controller to be adapted to various keyboard and display configurations.

Technical Specifications:

The UPD8279C-2 is typically packaged in a 40-pin DIP. It requires a 5V power supply. The device supports various keyboard modes, including encoded scan mode and decoded scan mode. It also supports various display modes, including left entry mode and right entry mode. The display characters are typically driven by external drivers. The FIFO stores up to 8 keyboard entries, preventing data loss during bursts of keyboard input.