External oscillator input

Welcome_123 · ‎2024-10-18

In application we are using MCU part no STM32G0KCIU6 of LQFP32 / UFQFPN32 - GP package, can external oscillator of frequency 16MHz (Example: Part no ASEMB-16.000MHZ-LY-T) can be connected to pin no 2 which is dedicated for LSE clock frequency 32KHz. As per datasheet Pin assignment and description list Pin No 2 of MCU has additional options to configure as OSC_IN whether this pin can be configured for HSE requirement? Can external oscillator of frequency 16MHz can be connected to this Pin?

SofLit · ‎2024-10-18

With Crystal oscillator you need to use only OSC_IN and in this package only OSC_IN is available:

So you need to use a Crystal oscillator not a Crystal/resonator.

Example: https://sourcewell.in/product/crystal-oscillators/

Hope it does answer your question.

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SofLit · ‎2024-10-18

Hello @Welcome_123 ,

There is no STM32G0KCIU6 device in ST portfolio, could you please provide the correct part number?

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Welcome_123 · ‎2024-10-18

MCU Part no STM32G0C1KCU6

Andrew Neil · ‎2024-10-18

@Welcome_123 wrote:
MCU part no STM32G0KCIU6

That doesn't seem to be a valid part number?

Looking at the STM32G0B1xB/xC/xE datasheet, the OSC32_IN specs are:

https://www.st.com/resource/en/datasheet/stm32g0b1kc.pdf#page=82

@Welcome_123 wrote:
Pin No 2 of MCU has additional options to configure as OSC_IN whether this pin can be configured for HSE requirement? Can external oscillator of frequency 16MHz can be connected to this Pin?

You mean OSC32_IN ?

Check the datasheet for the part you're actually using, but it looks like a NO.

Why not use the OSC_IN pin - which is specified for high-speed use:

STTwo-32 · ‎2024-10-18

I think you are toking about the STM32G0C1KCU6 or STM32G0B1KCU6, for both MCUs, the Pin 2 (PC14-OSC32_IN) can be used as OSC32_IN, OSC_IN so, you should be able to use a 16MHz oscillator on this pin.

Best Regards.

STTwo-32

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Andrew Neil · ‎2024-10-18

@Welcome_123 wrote:
MCU Part no STM32G0C1KCU6

Then this is the datasheet:

https://www.st.com/resource/en/datasheet/stm32g0c1kc.pdf#page=83

~~For 16MHz, you'd need to use OSC_IN - not OSC32_IN:~~ see correction below

EDIT - correction:

Ah - Now I see that pin 2, PC14, can be either OSC_IN or OSC32_in - so that should be OK?

SofLit · ‎2024-10-18

Hi @Welcome_123 ,

In this product, LSE and HSE are sharing the same pins and you can use HSE with an external Crystal oscillator on PC14 (HSE) in Bypass mode with 16MHz but you can't use LSE anymore:

These are the frequency ranges for HSE:

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Andrew Neil · ‎2024-10-18

@STTwo-32 wrote:
Pin 2 (PC14-OSC32_IN) can be used as OSC32_IN, OSC_IN

So it does!

But that makes Table 14 (which I cited earlier) a bit misleading: the limitation isn't on the pin (as the table suggests) - it's on whichever oscillator path its feeding...

Welcome_123 · ‎2024-10-18

@ Andrew Neil

MCU partno is STM32G0C1KCU6 can 48MHz or 16MHz external clock source connected to Pin 2 (PC14-OSC32_IN)?

SofLit · ‎2024-10-18

I've already answered that question:

You have a range of 4 to 48MHz as OSC_IN input frequency.

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