2026-04-22 5:58 PM - edited 2026-04-22 6:09 PM
CubeMX 6.17. When creating a new project for H533RETx or for the corresponding Nucleo-H533, SYSCLK is set at 32 MHz.
Not sure whether or not it is intended, but it looks like a trap for a new user, since the MCU datasheet talks about 250 MHz.
Instead, example projects for Nucleo-H533 (at least the couple that I've seen) quite reasonably run the MCU at 250 MHz, driven from the crystal present on the board.
2026-04-23 2:32 AM - edited 2026-04-23 2:54 AM
Hello,
Because the default clock source is set to HSI RC and it is divided then by 2 not over PLL which in my opinion correct (not a bug).
But Ok I will ask internally why it was not set to 250MHz by default while starting the project from a board.
Internal ticket for follow-up: CDM0062063 (not accessible by the community users).
2026-04-23 2:48 AM
@AlienBrother wrote:the MCU datasheet talks about 250 MHz.
That's the maximum speed - you don't have to run it at that speed.
2026-04-23 2:57 PM - edited 2026-04-23 3:20 PM
Ok, fair enough, perhaps the principle is that the default CubeMX configuration is similar to how the MCU is configured at startup (or by SystemInit() where CubeMX also generates some clock setup).
For Nucleo-H563ZI, CubeMX does in fact do something different: it sets up 250MHz from HSE (connected to ST-Link I think).
2026-04-24 12:00 AM
Hello,
Again this is not a bug as that doesn't lead to a non functional behavior of the default configuration but yes I do agree why it is set to an "optimal" clock configuration in a board and not in another. Just escalated the case internally yesterday as stated in my previous post. I'll get back to you as soon I have any feedback.
Thank you.