Bootloader getting bypassed and hung

Sudeep Chandrasekaran

Other Parts Discussed in Thread: MSP430F6733

Hi,

I am working with MSP430F6733 with CCS 5.5. The microcontroller has a custom bootloader written, which checks the flash bank integrity before jumping to the application code. Other than DVCC, the uC also has a backup power supply from AUXVCC1 (AUXVCC2 is grounded). If the DVCC line is power cycled frequently (about 1 Hz frequency), the bootloader sometimes gets bypassed. ie, about once every 5 power cycles, the bootloader does not run at all & the code execution directly begins from the application code. Also, once every 10 power cycles, the micrcontroller seems to get completely hung. I think the uC getting hung and the bootloader getting bypassed have the same root problem. Any directions on what causes the bootloader to get bypassed or the microcontroller to get hung at startup ?

Thanks, Sudeep

over 9 years ago

0 Jens-Michael Gross over 9 years ago

Guru 227245 points

Does DVCC go below the brownout threshold each power cycle? (capacitances may keep the MSP partly alive). What is your bootloader entry sequecne/detection? Or does the entry check function always return 'start the bootloader' without testing anything?

0 Sudeep Chandrasekaran over 8 years ago in reply to Jens-Michael Gross

Prodigy 130 points

Thanks for the direction.
DVCC does not go below the brownout threshold and when the DVCC goes below the brownout threshold the boot loader starts
on power up. Increasing the SVS thresholds in PMM and in turn resetting the system at a higher voltage seems to be a fix.

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Bootloader getting bypassed and hung