| 摘要 |
A method and apparatus provide a direct memory access (DMA) system that transfers data between a memory in a computer system and a plurality of I/O devices. The DMA system includes at least two channels which operate independently and in an interleaved manner so that multiple DMA transfers can occur concurrently. Each channel includes a pair of buffers so that data can be transferred between one buffer and memory at a rate determined by the memory and data can be transferred between the other buffer and the I/O device at a rate determined by the I/O device. Transfers between the two buffers occur at a data rate determined by the bus connecting the two buffers. Thus, the transfers between the two buffers occur in bursts to optimize the transfer and to reduce the amount of time that the bus is needed for the transfer. Therefore, the bus is available for transfers by the other DMA channel and by other devices on the bus.
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