Patent ID: 6735642
Filing Date: 2004-05-11
Classification: G06F

Abstract:
A method of direct memory access (DMA), comprising: receiving a first notification at a DMA engine that a first list of descriptors has been prepared, each of the descriptors in the list comprising an instruction for execution by the DMA engine and a link to a succeeding one of the descriptors, except for a final descriptor in the list, which has a null link; reading and executing the descriptors in the first list using the DMA engine; receiving a second notification at the DMA engine that a second list of the descriptors has been prepared; rereading at least a part of only the final descriptor in the first list to determine a changed value of the link, indicating to the DMA engine a first descriptor in the second list; and reading and executing the descriptors in the second list using the DMA engine responsive to the changed value of the link.