2025-03-06 3:31 AM
Hello,
I am working with the STM32L432KCU6 microcontroller and noticed that it includes a 32.768 kHz crystal. I would like to confirm whether there is a separate crystal for high-speed operation or if an external high-speed crystal needs to be added. Could someone clarify this for me? Any insights would be greatly appreciated.
Thank you!
Nikunj
2025-03-06 4:03 AM
LSI is not a crystal.
MCU will start off MSI or HSI. Check Datasheet and Reference Manual.
2025-03-06 4:07 AM - edited 2025-03-06 4:11 AM
Hello,
@Nikunj_17 wrote:
I am working with the STM32L432KCU6 microcontroller and noticed that it includes a 32.768 kHz crystal.
There is no MCU in this world embedding a crystal. The crystal needs to be added externally.
May be you are talking about a board? if that case, which board?
In case you need to add two crystals for LSE and HSE on your board.. yes they are separated.
PS: you said crystal oscillator but you need to know there are differences between Crystal (XTAL) and Crystal oscillator (XO). See this link.
2025-03-06 4:10 AM
Thanks for your answer!
Does this controller support an HSE crystal? Also, what is the actual function of PA0?
2025-03-06 4:16 AM - edited 2025-03-06 4:45 AM
Checking The datasheet of STM32L432KCU6. It's a UFQFPN32 package.
LSE is using PC14 and PC15
HSE is using only PA0 and that case you need to use a crystal oscillator (XO)
@Nikunj_17 wrote:
Does this controller support an HSE crystal? Also, what is the actual function of PA0?
No. Its doesn't support a Crystal for HSE but a Crystal oscillator (XO) as described in this link. XO has only one input that needs to be connected to PA0/CK_IN pin of the MCU.
Hope that helps.