Multimedia system and method of controlling data transfer between a host system and a network adapter using a DMA engine

Apparatus for controlling the delivery of data between a system and an adapter including a local processor, local processor memory and a local bus using a DMA engine, comprising the steps of:

• a) means for enabling the DMAengine by the local processor;
• b) means for issuing a request to the local bus interface by the DMA engine to fetch a first descriptor including a byte count field from local memory indicating a source and a destination for the transfer of data between the system and the local bus;
• c) means for issuing a request to the system and the local bus interface by the DMA engine using the first descriptor for the source to load a FIFO buffer and the destination to unload the FIFO;
• d) means for issuing a request that the destination empty the FIFO by the DMA when the descriptor byte count becomes zero;
• e) means for fetching the next descriptor linked to the first descriptor by the DMA engine;
• and
• f) means for issuing a request to the system and the local bus interface by the DMA engine for the source to load the FIFO buffer and the destination to unload the FIFO using the next descriptor.

An article of manufacture comprising:

• a computer usable medium having computer readable program code means embodied therein for controlling the delivery of data between a system and an adapter including a local processor, local processor memory and a local bus using a DMA engine, the computer readable program code means in said article of manufacture comprising:
• a) computer readable program code means for enabling the DMA engine by the local processor;
• b) computer readable program code means for issuing a request to the local bus interface by the DMA engine to fetch a first descriptor including a byte count field from local memory indicating a source and a destination for the transfer of data between the system and the local bus;
• c) computer readable program code means for issuing a request to the system and the local bus interface by the DMA engine using the first descriptor for the source to load a FIFO buffer and the destination to unload the FIFO;
• d) computer readable code means for issuing a request that the destination empty the FIFO by the DMA when the descriptor byte count becomes zero;
• e) computer readable program code means for fetching the next descriptor linked to the first descriptor by the DMA engine;
• and
• f) computer readable program code means for issuing a request to the system and the local bus interface by the DMA engine for the source to load the FIFO buffer and the destination to unload the FIFO using the next descriptor.