System and method for DMA transfer of data in scatter/gather mode
AssigneeCradle Technologies, Inc.
InventorsMoshe B. Simon, Erik P. Machnicki, Mark Longley
Life of this patent
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Abstract
A method and system for DMA transfer of data in scatter/gather mode. A table of buffer descriptors may be used to determine the next buffer to be used when a current buffer storing data that has been transferred or will be transferred and may be used in automatic buffer switching, which does not require processor intervention. Entries in the table of buffer descriptors are entered programmatically. The method and system also provide for hardware writing to table of packet descriptors which describes location and size of incoming data and can indicate whether a packet of data straddles two or more buffers, thus decoupling packet sizes from buffer sizes.
Claims9
A method of transferring data between a processor and an attached direct memory access (“DMA”) device in scatter/gather mode comprising:
- a) transferring a packet of data from the DMA device to the processor;
- b) detecting an end-of-packet condition;
- and
- c) writing out a packet descriptor to a table in memory, wherein the packet descriptor includes a packet start address, a packet size, and a bit indicating whether the packet is split across a buffer boundary.
Dependencies are inferred from the claim text.