entry to High-Speed Run (HSRUN) mode

[xx1]

Hi,

I am learning how to use the S32K144 board using the S32K-RM.

I want to enter to High-Speed RUN mode (HSRUN), and I found the method in S32K-RM as below. 

It seems there are two ways and I want to ask why in the first way we have to disable SPLL but in the next way we don't need to.

I hope to get your help.

Thank you!

[Julián_AragónM · Accepted solution]

Hi @xx1,

In the first method, you are changing the clock for RUN and HSRUN, and reconfiguring PLL back. The reference manual states: "Selecting a different clock source when in RUN requires that clock source to be enabled first and be valid before system clocks switch to that clock source."

In the second method, SPLL is configured at 80MHz in RUN mode and use this clock source in HSRUN, no changes to the clock are needed.

You can look into the following document for additional information: AN5425: Power Management for S32K1xx

Best regards,
Julián