#180 Issue resetting a blank then programmed part into run mode

[Alex Lennon]

Hi,

I ran into problems programming an stm32 part during a production process

ref: Device ID : 0x0435 (STM32L43xxx/44xxx)

• the part is blank
• the bootloader detects this and sets and persists an empty flash option byte
• we program using stm32flash
• we either issue an -R to reset or reset using the hardware reset pin

In either situation the empty flash option byte is not resampled so the bootloader still thinks the stm32 part is blank and refuses to enter application run mode.

The only way to enter application run mode is to completely power cycle the chip which causes it to resample the flag and it will then enter appliation run mode.

This isn't so much of a problem for a single board but when we are programming large numbers of boards in production it causes significant time delays and introduces compllexity to the production process which we'd rather avoid.

I have determined that there is a bootloader API command available to force resampling of the option bytes. I've implemented for -R and I have tested that this does work for us. I've committed my changes into a fork and offer them to you in case there is interest.

https://github.com/DynamicDevices/stm32flash/commit/2c10fe10c06bdb36a018a0abf65ebc98a10f8490

Cheers,

Alex Lennon