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Graduate II
October 11, 2022
Solved

Is there any problem when boot0 pin is floating?

  • October 11, 2022
  • 2 replies
  • 4132 views

Unfortunately, I wrongly designed the PCB board So, the boot0 pin is currently floating (no connectable evenif temporaliy because of BGA pin layout).

I'm getting trouble with programming. So,

I want to know whether the programming error is happening due to the boot0 pin.

Is there any problem when boot0 pin is floating?

    This topic has been closed for replies.
    Best answer by Tesla DeLorean

    I think the pin state issue can be addressed with suitable configuration of the option bytes.

    I think the debugger issue can be resolved with a debug script, or walking some configurations, mappings, and vector table address, such that the primary code of interest runs under the debugger.

    2 replies

    Technical Moderator
    October 11, 2022

    BOOT0 must have a fixed logical potential and is normally connected via a resistor or, if necessary, directly to GND. With a floating BOOT0, the pin would read in unforeseen random states during power-up.

    Regards

    /Peter

    KKIM.6Author
    Graduate II
    October 11, 2022

    I will order new PCB board but I also don't want to waste time. 

    So, I need to sure all the problem happens due to the boot0 pin.

    Currently, my design can make manual drill beneath the boot0 pin if I sacrifice Tx pin.

    I'll try this one. 

    But before doing this, I tried apply positive bias on the TX pin to induce negative bias on the boot0 pin using capacitive charging. (becasue TX pin is currenly passing beneth the boot0 pin) and I can start debug using SWD and STM32CubeIDE.

    But still, My programming has same error issue like below and the microcontroller only works one time and do not do next cycle (Turn-on GPIO pin and ADC start, send DMA data through USART). After restarting, still the microcontroller doesn't work properly.

    "Break at address "0x1fff5ee0" with no debug information available, or outside of program code."

    I think this problem happen due to not only on the PCB layout, but also in the programming.

    Is there any idea on this and do yo know how to solve the above issue?

    I'm currently using STM32WB55VGYTR6 microcontroller and programming it using ST-LINK inside the Neucleo-WB55 board.

    Graduate II
    October 11, 2022

    In most STM32 designs, ie those lacking specific control via the Option Bytes, floating BOOT0 will result in unpredictable operation related to start-up and supply rise times.

    Usually a pull-down facilitates predictable operation, and the ability to control the state on a programming or test fixture.

    The STM32WB looks to allow for programability via the option bytes, but you'll need to ensure that occurs because it's not the default state of the options.

    Large related thread on this topic https://community.st.com/s/question/0D53W00001rBMwiSAG/break-at-address-0x1fff5e8c-with-no-debug-information-available-or-outside-of-program-code-error

    KKIM.6Author
    Graduate II
    October 11, 2022

    I will order new PCB board but I also don't want to waste time. 

    So, I need to be sure all the problem happens due to the boot0 pin.

    Currently, my design can make manual drill beneath the boot0 pin if I sacrifice Tx pin.

    I'll try this one. 

    But before doing this, I tried to apply positive bias on the TX pin to induce negative bias on the boot0 pin using capacitive charging. (becasue TX pin is currenly passing beneth the boot0 pin) and I can start debugging using SWD and STM32CubeIDE.

    But still, My programming has the same error issue like below and the microcontroller only works one time and does not do next cycle (Turn-on GPIO pin and ADC start, send DMA data through USART). After restarting, still the microcontroller doesn't work properly.

    "Break at address "0x1fff5ee0" with no debug information available, or outside of program code."

    **This problem is what you are already commenting many times in another session.

    I think this problem happens not only in the PCB layout but also in the programming.

    Is there any idea on this and do you know how to solve the above issue?

    I'm currently using the STM32WB55VGYTR6 microcontroller and programming it using ST-LINK inside the Nucleo-WB55 board.

    Graduate II
    October 11, 2022

    I think the pin state issue can be addressed with suitable configuration of the option bytes.

    I think the debugger issue can be resolved with a debug script, or walking some configurations, mappings, and vector table address, such that the primary code of interest runs under the debugger.