In our project we use an Audio Codec to transmit and receive voice data. We have to use DMA instead of SSI FIFO. Because SSI has 15x32bit FIFO, it means it keeps about 1 ms voice data so we don't want to be occured interrupts every 1 ms. I understand that I have to use Peripheral DMA Units Copy Mode for this requirement.
In i.MX6 Reference Manuel document 18.104.22.168.7 section, it says "the peripheral DMA unit has a copy mode that is used when data transfers do not involve SDMA general registers. Data is read from the source target at a PSA address, stored in PD, and then automatically flushed to the destination target at the PDA address."
What do I understand? Is it not required to use SDMA scripts? Or is it used anyway?