stm32h503cbt isn't working with high frequency

[giangpa]

I am using STM32H503CBT6 with a frequency of 250MHz, but my program is not running. I have a counter variable in a while loop, but it is not incrementing. When I lower the frequency to 100MHz, the program works. Please help me!

[mƎALLEm]

Hello and welcome to ST community,

Are you sure about your clock config? what about the Flash wait states value?

Could you please share your project? What board are you using?

[Tesla DeLorean · Accepted solution]

Enough capacitance on VCAP pin(s), 2u2F on each or 4u7F total. Check placed capacitance, check voltage

Correct PLL settings, not excessive VCO frequency

Flash wait states?

[giangpa]

I only changed my clock config and the counter variable does not increment. Help me!

[Tesla DeLorean]

>> Help me!

Present better!

Show the specific code, show what's not incrementing.

Show board schematic if custom, name/link to board of commercially available.

[mƎALLEm]

You didn't answer my two questions:

1- What board are you using? if not ST board please share the schematics.

2- What Flash wait states you set?

Please attach your ioc file.

[mƎALLEm]

@giangpa did you accept as solution by mistake the answer from @Tesla DeLorean or it does really answered your question?

[giangpa]

 I think I have found my mistake. I designed the schematic myself, and as @Tesla DeLorean  said, it seems I chose the wrong capacitor. I should fix it right now. Thanks for help me, @mƎALLEm  @Tesla DeLorean