STM32L476 with external flash not work after re-power up
Posted: Sun Jul 28, 2019 4:30 am
I have diy a STM32L476RG board, with a 32KHz crystal and 1Mbytes external flash.
If I not using external 1Mbyte flash, it works fine. If I enable external flash, after upgrade firmware with ST dfuse util and click "leave DFU mode" button, it works and can read/write 1Mbytes pyb flash. But when I disconnect USB cable and reconnect again, it will not work, it will show pyb flash disk, but disk can't be read/write. And it maybe works after long time wait (several minutes) sometimes. And if I only enter DFU mode and click "leave DFU mode" button (not upgrade firmware), it will works.
What might have caused it?
I use micropython 1.11, and modify board define from STM32L476DISC.
If I not using external 1Mbyte flash, it works fine. If I enable external flash, after upgrade firmware with ST dfuse util and click "leave DFU mode" button, it works and can read/write 1Mbytes pyb flash. But when I disconnect USB cable and reconnect again, it will not work, it will show pyb flash disk, but disk can't be read/write. And it maybe works after long time wait (several minutes) sometimes. And if I only enter DFU mode and click "leave DFU mode" button (not upgrade firmware), it will works.
What might have caused it?
I use micropython 1.11, and modify board define from STM32L476DISC.