Connecting LSE to STM32L010?

[KevinZ]

Hello, all, and Happy New Year!

I'm trying to design my first microprocessor board. I'm trying to follow the guide given by Phil's Lab on YouTube, at https://youtu.be/nkHFoxe0mrU?si=Dx6cx6-a9yXncmEW, which I find very helpful. I'm using an STM32L010K4Tx in a device that is primarily a timer.

I'm not sure I need them, but I wanted to install a High Speed External crystal (HSE) and a Low Speed External crystal (LSE). In the STM32CubeIDE, I have a STM32L010K4Tx set up, and from the Pinout & Configuration Tab, I can select System Core -> RCC. Under RCC Mode and Configuration, I select High Speed Clock (HSE) and for Low Speed Clock (LSE), I select "Crystal/Ceramic Resonator." The pinout diagram seems to show pin 2:RCC_OSC32_IN and pin 3: SCC_OSC32_OUT, which is where I believe that I should connect either side of the HSE crystal and its capacitors. There's also pin 6: RCC_CK_IN but no RCC_CK_OUT pin.

Can someone help me configure the STM32L010K4 to include a LSE crystal or ceramic resonator, and teach me where and how to connect it? I've skimmed the STM32L101 Datasheet and the AN4467 Getting Started application note without finding an answer.

On a related note, is there a published Reference Board schematic for the STM32L010K family? Can someone point it out for me please?

Thanks, again, and happy holidays.

-Kevin

[Tesla DeLorean]

ST hides the schematics under the "CAD Resources" tab for the board products. They used to be in the User Manuals.

The L011 has a couple of internal clock sources (MSI, HSI, etc), which are quite usable for most things. There are things like CAN, ETHERNET and USB that expect particular precise clocks and need a HSE source. On the L011 you can use TCXO or other CMOS level clock sources.

The 32.768 KHz LSE allows for the RTC to update while the processor is in STANDBY mode.

[AScha.3]

👍

See here, how a simple test-board could be :

https://community.st.com/t5/stm32-mcus-products/stm32u575-simple-usb-vcp-uart/m-p/623805#M231287