Direct memory access moves data without CPU involvement.
DMA controllers move data between memory and peripherals without CPU involvement, interrupting only when finished or half done. Frees CPU for processing and enables high-throughput ADC, SPI and audio. Circular buffers allow continuous streaming; watch cache coherence.
An I²S audio stream is fed by DMA to a codec.
DMA moves data between peripherals and memory without the processor, which frees the CPU for other work and keeps high data rates manageable.
Direct memory access moves data without CPU involvement.
DMA moves data between peripherals and memory without the processor, which frees the CPU for other work and keeps high data rates manageable.
A hardware unit that performs memory transfers on request from peripherals, using its own address and count registers.
Cache coherence and buffer overwrites can cause corrupted data if the CPU and DMA access the same memory without synchronisation.
Typical applications include streaming ADC samples directly into a buffer without interrupts for each sample, sending a large display image from memory to an LCD controller and transferring audio samples continuously to a DAC.
Study "ADC peripherals and sampling" first (topic 69 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Channels and priorities. Double buffering. Burst transfers.
An I²S audio stream is fed by DMA to a codec.
The next topic is "Embedded C programming", which builds directly on this one.
It is classed as Intermediate in Electronics & Embedded (topic 70 of 104). It is an intermediate topic. Work through the beginner topics in Electronics & Embedded first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.