SWCU193A April 2023 – August 2024 CC2340R2 , CC2340R5 , CC2340R5-Q1
The µDMA driver should not disable µDMA when it has active transactions. The behavior when µDMA starts up again is not defined and by the time µDMA is reenabled, peripheral state and memory contents might have changed.
Software must also ensure that all µDMA channels from peripherals are disabled before entering standby, so no new requests are generated when µDMA is being disabled.
If the software doesn’t take care of turning off µDMA only after all ongoing µDMA transactions are completed, and instead turns the clocks off in the middle of a transfer sequence—µDMA only ensures that the current transaction is cleanly terminated and the bus does not hang—but it does not wait until all transactions within the ongoing sequence are completed (which might take an arbitrarily large amount of time).