SLAU923B June 2025 – April 2026 MSPM0H3216 , MSPM0H3216-Q1
The ULPCLK is the bus clock for peripherals in the PD0 power domain. It supports operation up to the max operating frequency and is derived directly from the MCLK tree . The ULPCLK frequency is dependent on the MCLK configuration and the selected power mode.
The PD0 power domain has a frequency limit of 32MHz in RUN and SLEEP modes.
| Selected Power Mode | Configuration | Register Settings | ULPCLK Frequency |
|---|---|---|---|
| RUN or SLEEP (32MHz maximum) | MCLK source is SYSOSC (RUN0, SLEEP0) | MCLKCFG.USELFCLK=0x0 | ULPCLK is sourced from MCLK according to the MCLK configuration with fULPCLK = fMCLK |
| MCLK source is LFCLK (RUN1/2, SLEEP1/2) | MCLKCFG.USELFCLK=0x1 or SYSOSCCFG.DISABLE=0x1 | ULPCLK is sourced from LFCLK with fULPCLK = fLFCLK = 32kHz | |
| STOP (4MHz maximum) | STOP with SYSOSC enabled (STOP0) | SYSOSCCFG.DISABLESTOP = 0x0 | ULPCLK is sourced from SYSOSC with fULPCLK = 4MHz |
| STOP with SYSOSC disabled (STOP2) | SYSOSCCFG.DISABLESTOP = 0x1 | ULPCLK is sourced from LFCLK with fULPCLK = fLFCLK = 32kHz | |
| STANDBY (32kHz maximum) | STANDBY with ULPCLK and LFCLK enabled (STANDBY0) | MCLKCFG.STOPCLKSTBY=0x0 | ULPCLK is sourced from LFCLK with fULPCLK = fLFCLK = 32kHz |
| STANDBY with ULPCLK and LFCLK disabled (STANDBY1) | MCLKCFG.STOPCLKSTBY=0x1 | ULPCLK is disabled to all peripherals except a few times, which receive fULPCLK=fLFCLK = 32kHz |