If I try to change frequency to 400 MHz then IDE show popup window: "Frequency searched for is out of range for this VOS range".

[LSet.1]

The maximum frequency I can set is 200 MHz.

STM32H743VIT6

CubeIDE 1.6.1

[LSet.1]

Yes, it works!

But there is one feature.

The "Power Regulator Voltage" (System Core, RCC) was in "Power Regulator Voltage 1" mode after setting the clock frequency to 400 MHz.

If I change the frequency to 200 MHz, then the Cube automatically calculate the settings. ОК, but it also switch the "Power Regulator Voltage" to "Power Regulator Voltage 3".

Now if I try again to specify the frequency of 400 MHz, then the Cube show popup window: "Frequency searched for is out of range for this VOS range".

If I return the "Power Regulator Voltage" back to "Power Regulator Voltage 1" mode and set the frequency at 400 MHz, then the Cube automatically calculates the settings again.

The Cube did not keep the first setting value "Power Regulator Voltage 1", although it was available for these frequencies.

[torgeirs]

For H753 it is documented like this:

3.5.3 Voltage regulator The same voltage regulator supplies the 3 power domains (D1, D2 and D3). D1 and D2 can be independently switched off. Voltage regulator output can be adjusted according to application needs through 6 power supply levels: • Run mode (VOS0 to VOS3) – Scale 0: boosted performance (available only with LDO regulator) – Scale 1: high performance – Scale 2: medium performance and consumption – Scale 3: optimized performance and low-power consumption.

To reach max freq, this MUST be used: Scale 0: boosted performance (available only with LDO regulator)

Mark and JW pointed us to where to set this in CubeMX.

Thank you. I had the same newbee problem