DMA (Bare-Metal)

Purpose

Configure DMA controllers for memory-to-peripheral and peripheral-to-memory transfers: channel/stream setup, burst sizes, circular mode, half-transfer interrupts, and cache coherency on Cortex-M7.

When to Use

• Offloading UART/SPI/ADC bulk transfers from CPU
• Audio/streaming double buffers
• Debugging DMA not triggering or corrupt data

Workflow

1. STM32 DMA2 stream (periph→mem)

/* UART2 RX DMA — Stream5, Channel 4 (verify RM matrix) */
RCC->AHB1ENR |= RCC_AHB1ENR_DMA1EN;