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chrkaras
Associate II
March 4, 2026
Question

STM32H755 HRTIM and USB multiplexing

  • March 4, 2026
  • 1 reply
  • 143 views

Hello everyone,

 

I am using the NUCLEO-H755ZI-Q board for a project. I have noticed that the HRTIMs that

are not multiplexed with some USB pins (like the HRTIM_D1 with the D+ for programming the IC via usb)

work normally, while if they do, I can't output any PWM pulse. Is this actually a thing and to overcome it

I have to remove some of the Zero Ohm resistors behind the nucleo board or design a custom pcb for my needs

or am I messing something up? In my situation specifically, i can output from all HRTIM channels except the D1

and D2, both of which map to a pin with USB.

 

Thanks in advance! 

1 reply

Technical Moderator
March 6, 2026

Hi @chrkaras 

Can you tell me which HRTIM outputs are you using ? Which resistors you removed?

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.Best regards,FBL
chrkaras
chrkarasAuthor
Associate II
April 21, 2026

Hi @FBL,

I tried using all HRTIM channels at once in the default pins that the cubemx assigns, and the only two that were not working are the D1 and D2 where both channels maps to the USB. I also had the same issue with the other channels when I reassigned them to other pins where there can be USB functionality. I DO NOT want to use the USB in my project, except when flashing the chip. Also I haven't disoldered any resistors. I am asking because I want to implement a custom board.

 

Thanks!