[STM32F405] flash strange behaviour
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‎2024-07-31 03:28 AM
Hello all,
I'm trying to lock the flash in level 1 mode. To do so, I'm using the provided ST APIs. In particular, I'm doing:
FLASH_Unlock(); // unlock flash to deal with it
FLASH_OB_Unlock(); // unlock option byte to deal with it
if(FLASH_OB_GetRDP() != SET) // check current protection status
{
FLASH_OB_RDPConfig(OB_RDP_Level_1);
FLASH_OB_Launch(); // launch the option byte writing procedure
}
FLASH_OB_Lock(); // lock option byte
FLASH_Lock(); // lock flash
Now, looking at the function implementations of the library, I can see something I'm not understanding in FLASH_GetStatus:
FLASH_Status FLASH_GetStatus(void)
{
FLASH_Status flashstatus = FLASH_COMPLETE;
if((FLASH->SR & FLASH_FLAG_BSY) == FLASH_FLAG_BSY)
{
flashstatus = FLASH_BUSY;
}
else
{
if((FLASH->SR & FLASH_FLAG_WRPERR) != (uint32_t)0x00)
{
flashstatus = FLASH_ERROR_WRP;
}
else
{
if((FLASH->SR & (uint32_t)0xEF) != (uint32_t)0x00)
{
flashstatus = FLASH_ERROR_PROGRAM;
}
else
{
if((FLASH->SR & FLASH_FLAG_OPERR) != (uint32_t)0x00)
{
flashstatus = FLASH_ERROR_OPERATION;
}
else
{
flashstatus = FLASH_COMPLETE;
}
}
}
}
/* Return the FLASH Status */
return flashstatus;
}
Specifically, it is checking the SR register with mask EF. Looking at datasheet it means that we are taking into consideration also the reserved bits an the bit 0.
I created an other project using stm32cubeIDE version 1.15.0 and found out that in the new version of library the implementation is a bit different
if(__HAL_FLASH_GET_FLAG((FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR | FLASH_FLAG_PGAERR | \
FLASH_FLAG_PGPERR | FLASH_FLAG_PGSERR)) != RESET)
The library does not check reserved bits and does not check EOF bit.
So, what bits should I check?
With debugger I read the content of SR register and the value is 0xC0 which means that I have the PGSERR and PGPERR bits set to 1.
Now, If I ignore that 2 bits everything work as expected and the flash get protected but I need to understand If I can safely ignore them and why that bits are set? The procedure I'm performing should be correct.
Is there something documented in some ERRATA?
Thanks for the answer.
Marco.
Solved! Go to Solution.
- Labels:
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Flash
-
STM32CubeMX
-
STM32F4 Series
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‎2024-08-01 06:16 AM
Yes, clear those flags and use the intended HAL_FLASHEX_* functions.
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‎2024-07-31 06:17 AM
The debugger can do things that cause PGSERR and PGAERR to be set when the program starts. Clear those flags on program start if you want.
FLASH_OB_GetRDP and FLASH_OB_RDPConfig aren't meant to be called directly, but rather via HAL_FLASHEx_OBGetConfig/HAL_FLASHEx_OBProgram.
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‎2024-08-01 03:32 AM
Hello I will try to log the flash register without any debugger interaction to see if this could cause the issue.
I will also try to find HAL_FLASHEx_OBGetConfig/HAL_FLASHEx_OBProgram if are defined somewhere into the code.
So, your advice could be to make a reset of flags at the beginning?
Thanks,
Marco.
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‎2024-08-01 06:16 AM
Yes, clear those flags and use the intended HAL_FLASHEX_* functions.
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‎2024-08-06 12:11 AM
Hello, looks like that debugger was causing that bits to be set