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Ixiasoft
Visible to Intel only — GUID: wou1655792070088
Ixiasoft
7.9. Using DMA Devices
In the HAL DMA device model, there are two categories of DMA transactions: transmit and receive. The HAL provides two device drivers to implement transmit channels and receive channels. A transmit channel takes data in a source buffer and transmits it to a destination device. A receive channel receives data from a device and deposits it in a destination buffer. Depending on the implementation of the underlying hardware, software might have access to only one of these two endpoints.
Copying data from memory to memory involves both receive and transmit DMA channels simultaneously.
The API for access to DMA devices is defined in sys/alt_dma.h.