DMA Controller Operation

All receiver audio channels can be assigned to a single DMA Controller channel or individual audio channels can be assigned to one DMA Controller channel per audio channel. The same channel assignment choice applies to the transmitter audio channels.

Channel assignment is selected by writing to the I2SC_MR.RXDMA and I2SC_MR.TXDMA bits. If a single DMA Controller channel is selected, all data samples use I2SC receiver or transmitter DMA Controller channel 0.

The DMA Controller reads from the I2SC_RHR and writes to the I2SC_THR for both audio channels successively.

The DMA Controller transfers may use 32-bit word, 16-bit halfword, or 8-bit byte depending on the value of the I2SC_MR.DATALENGTH field.