DIRECT MEMORY ACCESS CONTROLLER

摘要

Systems and methods for direct memory access are described. One example system includes a memory module that includes a first memory portion that maintains transfer descriptors of direct memory access (DMA) channels, and a second memory portion that maintains transfer descriptors of enabled DMA channels. The system includes a controller coupled to the memory module, the controller includes one or more DMA channels coupled to a system bus, a channel arbiter that selects one of the enabled DMA channels as an active DMA channel for data transfer including re-arbitrating after each burst or beat in a given transfer, and an active channel buffer that receives a transfer descriptor of the active DMA channel from the second memory portion. The controller is configured to write back the transfer descriptor of the active DMA channel into the second memory portion when the active DMA channel loses arbitration.

主权项

1. A system comprising:
a memory module including:
a first memory portion that maintains transfer descriptors of direct memory access (DMA) channels, anda second memory portion that maintains transfer descriptors of enabled DMA channels; and a controller coupled to the memory module, the controller including:
one or more DMA channels coupled to a system bus,a channel arbiter that selects one of the enabled DMA channels as an active DMA channel for data transfer based on one or more criteria including re-arbitrating after each burst or beat in a given transfer, andan active channel buffer that receives a transfer descriptor of the active DMA channel from the second memory portion,wherein the controller is configured to write back the transfer descriptor of the active DMA channel into the second memory portion when the active DMA channel loses arbitration during data transfer.