SWCU191 February 2022 CC1311P3 , CC1311R3 , CC2651P3 , CC2651R3 , CC2651R3SIPA
If the system bus is turned off, the I2S DMA loses access to RAM and flash.
The system bus is turned off if all of the following conditions are true:
For lowest current consumption, set PRCM:SECDMACLKGDS.DMA_CLK_EN = 1 (loaded with PRCM:CLKLOADCTL) to keep the system bus enabled for the I2S DMA.