SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
The high-speed clock (HSCLK) is the output of the high-speed clock selection mux, and can be selected to source MCLK by setting the USEHSCLK bit in the MCLKCFG register. The HSCLK is only a selection option for MCLK; it does not source any other functions. HSCLK can be configured to be sourced from the the HFCLK (HFXT or HFCLK_IN). To change the HSCLK source to HFCLK, set the HSCLKSEL bit in the HSCLKCFG register.
The HSCLK is only available in RUN and SLEEP modes. It is automatically disabled by SYSCTL in all other modes, along with the HFXT (if enabled).
SYSCTL will not switch MCLK to HSCLK, even if requested by software, if the HSCLK status check indicates that selected HSCLK source was not started correctly.