Direct Memory Access Controller (DMAC)
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Fig 9-38 Flow control configurations
9.2.10
Peripheral Burst Transaction Requests
For a source FIFO, an active edge is triggered on dma_req when the source FIFO exceeds some watermark level. For a destination FIFO, an
active edge is triggered on dma_req when the destination FIFO drops below some watermark level.
This section investigates the optimal settings of these watermark levels on the source and destination peripherals and their relationship to,
respectively:
Source transaction length, CTLx.SRC_MSIZE
Destination transaction length, CTL
x
.DEST_MSIZE
For demonstration purposes, a receive SSI is used as a source peripheral, and a transmit SSI is used as a destination peripheral.
Note
: Throughout this section, SSI-related parameters are prefixed with “SSI”. DMAC-related parameters are prefixed with “DMA”.
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2019-05-15 10:08:03