STM32L0x clock

[Scott Dev]

Posted on January 31, 2017 at 19:02

Hi

  I am new to the STM32L0x processor, and have moved from a freescale 8 bit controller. The first thing I am looking at is the system clock. I have a few questions hopefully someone can help? Many Thanks

I understand the 2 external oscillators, HSE and LSE. I am planning to design low power applications, and not sure if I have picked this up correctly, as only used to 1 system clock:

  1. If I use an extarnal 32.768Kz external crytal for the LSE, I see it can be used for the RTC, can this be used as a clock for the UART, and timer channels?

  2. If I do number 1., do i use an internal clock for the SYSCLK?

Many Thanks

Scott

[waclawek.jan]

Posted on January 31, 2017 at 19:36

In the RM (which depends on the exact part number), there is a whole-page clock schematics in the RCC chapter.

The answer to your questions is probably no (at least not directly, you may be able to condition the HSI by LSE using a timer and software), but I don't use the 'L0s so it's up to you to figure out the details.

JW

[Nesrine M_O]

Posted on February 01, 2017 at 11:02

Hi

devlin.scott

,

Welcome to STM32 community

As it is said by

Waclawek.Jan

, you have first to refer to Reset and clock control(RCC) chapter in your related reference manual (Clock tree).

As newbie with STM32 family,I recommend you to download the

http://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-configurators-and-code-generators/stm32cubemx.html

which is a graphical software configuration tool that allows generating C initialization code using graphical wizards.( refer

http://www.st.com/content/ccc/resource/technical/document/user_manual/10/c5/1a/43/3a/70/43/7d/DM001047pdf/files/DM001047pdf/jcr:content/translations/en.DM001047pdf

User manual for further details about CUBEMX)

-Nesrine-

[Scott Dev]

Posted on February 02, 2017 at 13:40

Thanks for the reply