SWCU192 November 2021 CC1312R7 , CC1352P7 , CC2652P7 , CC2652R7
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.