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Aurélien f
Associate III
December 3, 2018
Solved

STM8L001J3 : SWIM and reset pin

  • December 3, 2018
  • 2 replies
  • 3665 views

Hello,

I would like to use the STM8L001J3. I am very new with STM8 family. I used to using STM32. STM8L001J3 seems to be great for my application, i started to draw the schematics but i wonder how to connect the debug probe. For VCC, VSS, and SWIM pin, it is ok, but there isn't nRESET pin ... How the probe could monitor the CPU without reset ? Am i wrong ?

Thank you in advance.

Best regards,

Aurélien

    This topic has been closed for replies.
    Best answer by Mon2

    Hi @Aur�lien f​, we are using the STM8S001J3 (similar to your device) in a new design and the product is very simple to use.

    You only require SWIM pin + Ground and use the low cost STM8 Discovery kit (8 pin version is what we have the in lab) and you can reflash this target micro at anytime.

    There is no RESET pin. However, there is an internal POR and other forms of reset.

    If possible, dedicate the SWIM pin for only this purpose otherwise you must respect the power up timing delay BEFORE using the SWIM pin as an I/O pin. The key reason being that if you immediately convert with your code the SWIM pin to be a GPIO pin then the external SWIM tool may not be able to access the same CPU. That is, you will BRICK the CPU. You must allow for some power up delay for the SWIM tool to work.

    Hope this helps.

    2 replies

    pvo317
    Associate
    May 1, 2019
    Mon2
    Mon2Best answer
    Senior III
    May 1, 2019

    Hi @Aur�lien f​, we are using the STM8S001J3 (similar to your device) in a new design and the product is very simple to use.

    You only require SWIM pin + Ground and use the low cost STM8 Discovery kit (8 pin version is what we have the in lab) and you can reflash this target micro at anytime.

    There is no RESET pin. However, there is an internal POR and other forms of reset.

    If possible, dedicate the SWIM pin for only this purpose otherwise you must respect the power up timing delay BEFORE using the SWIM pin as an I/O pin. The key reason being that if you immediately convert with your code the SWIM pin to be a GPIO pin then the external SWIM tool may not be able to access the same CPU. That is, you will BRICK the CPU. You must allow for some power up delay for the SWIM tool to work.

    Hope this helps.

    Nm.1396
    Associate
    November 20, 2019

    Hi Mon2,

    I tried to reset the by trying to pull the SWIM low. But cannot reset. I am not using Pin8 for other functionality. Can you kindly suggest me on how to reset