PEP in FLASH_0.MCR cleared automatically while EHV=0

[Yannek]

Hi,

The PEP flag (of FLASH_0.MCR) should be set when I try to write to protected block of flash.

I observe, that this flag is cleared automatically at the moment of clearing EHV flag.

Is it intended and should be written in RM? Or do I do something wrong?

uint8_t DoFlashing (void ) {
	// clear potential error flags
	FLASH_0.MCR.R |= FLASH_0_MCR_ERROR_FLAGS;
	// start erasing/program
	FLASH_0.MCR.B.EHV = 1; // here PEP gets 1 because flash is LOCKED
	// active wait to be finished
	while (!FLASH_0.MCR.B.DONE) {}
	FLASH_0.MCR.B.EHV = 0; // here PEP returns to 0
	FLASH_0.MCR.B.ERS = 0;
	FLASH_0.MCR.B.PGM = 0;
	if (FLASH_0.MCR.B.PEP) {
 // DOES NOT WORK !!!
		return FALSE;
	}
	return FLASH_0.MCR.B.PEG;
}

Best,

Yannek

[Erwan YVIN]

Hello Yannek ,

Have you solved your issue ?

Could you check if you respect the transition ?

 

Have you unlocked the flash ?

// unlock all
 FLASH_0.LOCK0.R = 0;
 FLASH_0.LOCK1.R = 0;
 FLASH_0.LOCK2.R = 0;
 FLASH_0.LOCK3.R = 0;

Best regards

Erwan

[Yannek]

Hi Ervan,

Of course I have not unlocked the flash, because I am testing the PEP flag, not ERS. My purpose is to report failure due to attempt to write or erase locked flash.

I have discovered that I need check read PEP flag before I clear EHV. Otherwise PEP gets cleared as soon as I clear EHV. Afterwards I can't check why flash write/erase failed.

I'm finding this ambiguous: manual says that I have to clear this flag before another flashing, but this never happens, because UC clears PEP itself.

Best,

Yannek