VOSF bit confusion

[skoe]

Posted on April 27, 2016 at 10:16

RM0038 says (5.1.6) that one has to wait for VOSF (Voltage Scaling select flag) when changing the voltage range using VOS. The same page contains a note that says that ''the system clock is stopped until the regulator is stabilized (VOSF=0)''.

Question 1: Does it make sense to poll this bit when the CPU is not running anyway? Question 2: If it makes sense, is it also needed to wait for VOSF after I decreased the core voltage? Thomas

[Andrew Sund]

Posted on August 09, 2017 at 01:47

Way late, but I also find this curious. It's also asked and unanswered in:

https://community.st.com/0D70X000006SJBHSA4

I stumbled across this question because the CubeMX software generates a standalone:

__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

My coworkers have inserted polling loops into the code per the manual, but I suspect they are 'fixing' some other problem...

[nkatch]

Posted on August 14, 2017 at 11:44

I have the same question... I will insert the requested 'poll' but it seems pointless on the information given.