How does the DMA work when data is to be transferred from the host to the device?
When PDIUSBD12 is set to the DMA mode, on receipt of a full packet of data from Endpoint 2, the DMReq is asserted to allow the DMA controller to retrieve the data from the PDIUSBD12’s Internal Buffer. The Read_N of the PDIUSBD12 is to be asserted by the DMA Controller. The PDIUSBD12 does not have an internal buffer to keep track how many bytes have been transferred via DMA.
