Microchip Technology Incorporated
DMA-Scatter and Gather Operations for Non-Contiguous Memory

Abstract:

A direct memory access (DMA) controller, includes circuitry configured to load a DMA transfer descriptor configured to define which memory elements within a contiguous block of n memory elements are to be included in a given DMA transfer. The circuitry is further configured to, based on the DMA transfer descriptor, determine whether each memory element within the contiguous block of n memory elements is to be included in the given DMA transfer, including a determination that two or more non-contiguous sub-blocks of memory elements within the contiguous block of n memory elements are to be transferred. The circuitry is further configured to, based on the determination of whether each memory element within the contiguous block of n memory elements is to be included in the given DMA transfer, perform the DMA transfer of memory elements determined to be included within the given DMA transfer.