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MSP432P401R: Doubt in MSP432 BSL Hardware Invocation sequence

Prodigy 40 points

Replies: 2

Views: 72

Part Number: MSP432P401R

I was going through the MSP432 BSL User guide and I had one doubt which I want to ask

I understand that in order to perform hardware invocation of the BSL, we need to program the flash mail box with MB_START, CMD and other appropriate parameters and do a reboot.

Bootcode will now take the control and it will see boot override request and it will perform the request by parsing the flash mailbox and associated CMD.

If the boot override command is BSL_CONFIG, I can see that the bootcode executes the command and write 0x00000ACE to the ACK (0x1F4 offset from flash mailbox start address) and writes NONE (0x00000000) to the CMD field (0X04 offset from the flash mailbox start address). 

My doubt is "TI mentions that once you have provided the pins and their state for the hardware sequence entry, the device will go into BSL mode if the same sequence is present during boot time". 

But I think that bootcode first checks the command field and if the command is BSL_CONFIG, it extracts the BSL hardware invoke parameters (0x1E8 offset from flash mailbox). Since, BSL writes none to this field on successful execution of command, on next reboot how does the bootcode knows that it has to enter into the BSL (based on the hardware sequence entry) since the command is NONE by now.

Please help me understanding this part of BSL.

  • Hi,

    Based on my understanding of the BSL, wouldn't the device clearing the flash mailbox after the bootloader is run once be correct behavior? Have you tried running the BSL code to see what results you get if you perform the steps indicated in your post?

    Regards,

    Michael

  • In reply to Michael Reymond:

    Hi,

    I assume that you have resolved your issue since I have not heard back from you. If not, feel free to post a response to this thread, or open a new thread regarding this issue.

    Regards,
    Michael