What is the minimum settings of QE sdma?

[yunyuaner]

Hi,

To make sdma work, what are the minimum settings? Is the sdma data transfer transparent to software? Take ucc_uart for example, to transfer serial data from qe to external memory, I need to setup the buffer descriptor and mark it as ready, then should the sdma take effect? I mean, there isn't further software operation on sdma, right?

Thanks

Jia

[alexander_yakov · Accepted solution]

SDMA is Serial DMA channel, used by QE to communicate with system memory. This physical channel is split to a number of virtual SDMA channels, 2 channels per each QE communication controller, one for RX and one for Tx. You do not need to make any settings with SDMA itself to make it working, all SDMA-related initialization is performed as a part of communication controller initialization. However, SDMA has its own SDMA-specific registers, used mostly to handle SDMA errors (bus errors) and for other purposes. Please look QE Reference Manual, Section 3.1.8 for more details.