How to optimize MCU interrupt response time?
Optimizing MCU interrupt response time is crucial for real-time performance and accurate signal processing. Below are practical, layered strategies to reduce latency and improve the efficiency of your interrupt handling: 1. Minimize Interrupt Latency (Time Until ISR Starts) What causes latency? Instruction execution delay Stack saving (context switch) Nested interrupts disabled Peripheral delay (e.g., slow flag clearing) Optimization Techniques: Tip Description Enable fast interrupt mode (if supported) Some MCUs (e.g. ARM Cortex-M3+) support tail-chaining or fast ISR entry Use high-priority interrupts Assign highest priority to critical ISRs Avoid global interrupt disable ( __disable_irq() ) Keep interrupts globally enabled as much as possible Use vectorized interrupt handling Avoid shared interrupt vectors; direct vector → faster Place ISR in RAM (if allowed) Running code from RAM can be faster than Flash on some MCUs 2. Write Ef...