How to determine the performance limit of a microcontroller?
Determining the performance limit of a microcontroller ( MCU ) involves evaluating both hardware capabilities and software efficiency. Here’s a systematic approach to identify bottlenecks and maximize performance: 1. Hardware-Centric Evaluation Clock Speed & Core Architecture Base Frequency : Check datasheet for max CPU clock (e.g., STM32H7 @ 480 MHz). Core Type : ARM Cortex-M4/M7 vs. RISC-V (DMIPS/MHz comparison). Overclocking Risks : Thermal throttling, flash wait states. Memory Constraints Parameter Impact Measurement Tool Flash Size Limits code complexity Map file analysis (e.g., arm-none-eabi-size ) RAM Usage Heap/stack overflows crash system FreeRTOS uxTaskGetStackHighWaterMark() Cache Hit Rate Critical for high-speed cores (Cortex-M7) DWT (Data Watchpoint) counters Peripheral Throughput DMA Utilization : Offload CPU (e.g., SPI @ 50 Mbps with DMA vs. 8 Mbps without). Bus Contention : AHB/APB bottlenecks (check bus matrix in reference manual). 2. Software P...