SLAZ741D March 2023 – August 2025 MSPM0L1105 , MSPM0L1106 , MSPM0L1303 , MSPM0L1304 , MSPM0L1305 , MSPM0L1306 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346
SYSOSC Module
Functional
MFCLK does not work when Async clock request is received in an LPM where SYSOSC was disabled in FCL mode
MFCLK will not start to toggle in below scenario:
1. FCL mode is enabled and then MFCLK is enabled
2. Enter a low power mode where SYSOSC is disabled (SLEEP2/STOP2/STANDBY0/STANDBY1).
3. Async request is received from some peripherals which use MFCLK as functional clock.
On receiving async request, SYSOSC gets enabled and ulpclk becomes 32MHz. But MFCLK is gated off and it does not toggle at all as the device is still set to the LPM.
If SYSOSC is using the FCL mode - Do not enable the MFCLK for a peripheral when you're entering a LPM mode which would typically turn off the SYSOSC.