Unable to get maximum SYSCLK of 480MHz on STM32H743XIH

[DavidO]

With SYSCLK set to 400MHz in MX Clock Configuration there is no problem, but any setting above ~420 up to the maximum of 480Mhz causes the system to 'crash' during initialisation in HAL_RCC_ClockConfig(..). More specifically when or after RCC->CFGR is updated with the clock source. Cortex_M7 is not currently configured. Has anyone experienced something similar?

[TDK]

What does crash mean here specifically? Is this a custom board?

[Nsg1987]

Hello @DavidO 

Please refer example from CubeMX "PWR_VOS0_480MHZ".

you need to do following settings.

HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);

__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);

I hope this helps

[DavidO · Accepted solution]

Yes, PWR_REGULATOR_VOLTAGE_SCALE0 works.  Many thanks. I had to force that setting, though, because it is not available in CubeMx. The key it seems to the higher clock rate is to set the overdrive bit in the SYSCFG power control.  This is a feature of the STM32H74 and STM32H75 series. Power overdrive must be disable before going into low power mode, but will not happen in my scenario.

[Foued_KH]

Hello @DavidO , 

You can follow the steps in this article : How to reach 480MHz for STM32H7xx MCUs ? - STMicroelectronics Community
Foued