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Associate III
August 12, 2025
Question

Query on STM32G4A1VET6 OSC_IN & OSC_OUT pins

  • August 12, 2025
  • 1 reply
  • 302 views

Hello, Currently we are using STM32G4A1VET6 MCU in our board and we dont have any high speed application in the board, suppose i dont want to use any crystal/oscillator on these pins, then how these pins should be taken care in our schematic, I checked in the documents regarding thsi but it is not mentioned what to do with these pins if we dont connect any crystal/oscillator how can we terminate or can we use it as GPIO, could you please provide the supporting documents for these?

1 reply

STTwo-32
Technical Moderator
August 12, 2025

Hello @Meghna 

According to the chapter 9.3.13 of the RM0440 Rev9, When the HSE or LSE oscillator is switched OFF (default state after reset), the related oscillator pins can be used as normal GPIOs.

Best Regards.

STTwo-32

MeghnaAuthor
Associate III
August 19, 2025

Hello, i got your point of HSE or LSE being switched off after reset, but in the condition where in our board we dont have any high speed application, then 1.how about if we are not using any oscillator/crystal/external clock source for OSC_IN & OSC_OUT pins ? 2. Will LSE alone support 12Mbps for USB operation?

Mike_ST
Technical Moderator
August 19, 2025

Hello,

>> 1.how about if we are not using any oscillator/crystal/external clock source for OSC_IN & OSC_OUT pins ?

Please read the section 7.2 of the reference Manual mentionned above. You will learn about the clocks.

In short, use HSI16 (default)

>> 2. Will LSE alone support 12Mbps for USB operation?

No, please activate HSI48 for USB.