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STM32F030C8 not entering Read Memory Level 1

Joe.H
Associate III

STM32F030C8 - I'm not using any of the ST libraries.

I'm attempting to secure the mcu.

I unlock flash and unlock the option write - verified.

I am using a J-Link debugger to verify the process.

Option byte before process == 0xaa55 - or level 0 access

I erase the option bytes and verify that they are 0xffff.

I program 0x11 into the option byte and verify that the option bytes read 0x11ee

I execute the following instruction to enter level 1 read access

FLASH->CR |= FLASH_CR_OBL_LAUNCH;

The mcu resets as expected.

I can still connect to the mcu using the J-Link debugger and debug as if the mcu was at level 0 again. Reading the option bytes show that indeed I'm back at level 0 with the option bytes being 0xaa55.

Any ideas or comments as to why the mcu is reverting back to level 0?

Thanks

1 REPLY 1
Joe.H
Associate III

The mcu was really at level 1.

The J-link was not stating that the device was secure and was automatically erasing and performing a bulk erase without letting me know.

Addressed the J-link notification issue and now I can confirm I am actually securing the device.

Closed.