2025-08-12 5:04 AM
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?
2025-08-12 5:54 AM - edited 2025-08-12 5:54 AM
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
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.
2025-08-19 4:20 AM
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?
2025-08-19 6:32 AM
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.