Working with Microchip PIC 8-bit Interrupts

Working with Microchip PIC 8-bit Interrupts

Luther Stanton

Still RelevantIntermediate

This fifth and final post of the Getting Started with Microchip PIC 8 Bit Development series looks at interrupts on 8-bit PIC microcontrollers. After a review of basic interrupt functionality, actual implementation is explored through implementation of a four bit counter driven via Timer0 interrupts whose value is displayed through four LEDs on Microchip's Curiosity HPC Development Board.

Summary

This post teaches how interrupts work on Microchip 8-bit PIC microcontrollers and shows a practical implementation: a Timer0-driven four-bit counter displayed on four LEDs of the Curiosity HPC board. Readers will learn the interrupt setup, ISR structure, and board-specific GPIO mapping needed to build and debug a simple bare-metal interrupt-driven application.

Key Takeaways

Configure Timer0 and its prescaler to generate periodic interrupts for timing tasks
Implement an interrupt service routine (ISR) in XC8/C that correctly handles context and shared data
Use volatile variables and atomic access techniques to avoid race conditions between ISRs and main code
Map Curiosity HPC GPIO pins and drive LEDs from interrupt-updated state
Debug and validate interrupt behavior using breakpoints, single-step, and peripheral flag checks

Who Should Read This

Embedded engineers or students with basic MCU/C knowledge who want practical, hands-on guidance implementing and debugging interrupts on 8-bit PICs for firmware and bare-metal projects.

Still RelevantIntermediate