7.2.6.12 DMA Controller Operation

All receiver audio channels and all transmitter audio channels are each assigned to a single DMA Controller channel.

The DMA Controller reads from the I2SMCC_RHR and writes to the I2SMCC_THR for all 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 I2SMCC_MRA.DATALENGTH field.

The DMA chunk size field (DMACHUNK) of the Mode Register B (I2SMCC_MRB) should correspond to the DMA channel configuration. The supported chunk according to the configuration is available in the two tables below

Note that when I2SMCC_MRB.PACK24=1, the DMA chunk size is limited to 1 word.

Table 7-7. TX DMA Chunk Configurations
FORMAT	TXMONO	DATALENGTH	NBCHAN	I2SMCC_MRB.DMACHUNK Configuration⁽¹⁾	Maximum DMA Chunk Size Allowed
0 or 1 (I²S or LJ)	0 (Stereo)	0, 1, 2, 3, 4 or 6 (32, 24, 20, 18, 16 or 8 bits)	No effect	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	8-word chunk
	1 (Mono)			0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
	0 or 1 (Stereo or Mono)	5 or 7 (16 bits compact or 8 bits compact)		0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
2 or 3 (TDM or TDMLJ)	No effect	No effect	0 (1 channel)	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
	0 (Stereo)	0, 1, 2, 3, 4 or 6 (32, 24, 20, 18, 16 or 8 bits)	1, 3 or 7 (2, 4 or 8 channels)	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	8-word chunk
			2, 4, 5 or 6 (3, 5, 6 or 7 channels)	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
	1 (Mono)		1, 3 or 7 (2, 4 or 8 channels)	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
			2, 4, 5 or 6 (3, 5, 6 or 7 channels)	0	1-word chunk
				1	2-word chunk
				2
				3
	0 or 1	5 or 7 (16 bits compact or 8 bits compact)	1, 3 or 7 (2, 4 or 8 channels)	0	1-word chunk
				1	2-word chunk
				2	4-word chunk
				3	4-word chunk
			2, 4, 5 or 6 (3, 5, 6 or 7 channels)	0	1-word chunk
				1	2-word chunk
				2
				3

Note: When I2SMCC_MRB.PACK24=1, the DMA chunk size is limited to 1 word.

Table 7-8. RX DMA Chunk Configurations
FORMAT	DATALENGTH	NBCHAN	I2SMCC_MRB.DMACHUNK Configuration⁽¹⁾	Maximum DMA Chunk Size Allowed
0 or 1 (I²S or LJ)	0, 1, 2, 3, 4 or 6 (32, 24, 20, 18, 16 or 8 bits)	No effect	0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	8-word chunk
	5 or 7 (16 bits compact or 8 bits compact)		0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	4-word chunk
2 or 3 (TDM or TDMLJ)	No effect	0 (1 channel)	0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	4-word chunk
	0, 1, 2, 3, 4 or 6 (32, 24, 20, 18, 16 or 8 bits)	1, 3 or 7 (2, 4 or 8 channels)	0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	8-word chunk
		2, 4, 5 or 6 (3, 5, 6 or 7 channels)	0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	4-word chunk
	5 or 7 (16 bits compact or 8 bits compact)	1, 3 or 7 (2, 4 or 8 channels)	0	1-word chunk
			1	2-word chunk
			2	4-word chunk
			3	4-word chunk
		2, 4, 5 or 6 (3, 5, 6 or 7 channels)	0	1-word chunk
			1	2-word chunk
			2
			3

Note: When I2SMCC_MRB.PACK24=1, the DMA chunk size is limited to 1 word.