Writing to Flash - PGAERR (Programming alignment error)

[steve239955_st]

Posted on March 31, 2016 at 16:19

So I haven't got my flash routine working yet on the STM32L476, this time it's another error.

I don't quite understand how this one is possible: Here the code:

bool
flash_program_buffer(uint64_t* dest, 
const
uint64_t* source, 
size_t
len)
{
while
(FLASH->SR & FLASH_SR_BSY) {} 
// 1. wait until not busy
FLASH->SR = FLASH->SR; 
// 2. clear error flags
FLASH->CR |= FLASH_CR_PG; 
// 3. set PG bit
for
(
size_t
i=0; i<len; ++i)
{ 
// 4. write data dword
((uint32_t*) &dest[i])[0] = ((uint32_t*) &source[i])[0];
((uint32_t*) &dest[i])[1] = ((uint32_t*) &source[i])[1];
while
(FLASH->SR & FLASH_SR_BSY) {} 
// 5. wait until not busy
if
(FLASH->SR & FLASH_SR_EOP) 
// 6. Check EOP flag in FLASH_SR (operation succeeded), and clear it
{
FLASH->SR &= ~FLASH_SR_EOP;
}
// else... ERROR ?
}
FLASH->CR &= ~FLASH_CR_PG; 
// 7. clear PG bit if there is no more programming request
return
!(FLASH->SR & FLASH_SR__MASK_ANY_ERROR);
}

Note that preceding the call to that function, the unlock sequence and then a mass erase on that bank are performed. Now, the address passed as ''dest'' pointer is the very beginning of flash bank 2, 0x08080000. This looks quite 64-bit aligned to me. If I understand the manual correctly, I am to write one part of a double-word to a 64-bit aligned address, then write the second part of the double-word. Which is done here. But after the very first iteration of the loop, the status register has the value 160, i.e. bit5 and bit7 are set:Bit 5, PGAERR: Programming alignment error,Bit 7, PGSERR: Programming sequence error. What is the cause of this? Thanks in Advance #stm32l476-flash

[Tesla DeLorean]

Posted on March 31, 2016 at 17:18

Check what else is set in the CR

Make sure the memory you are writing is in fact blank.

Is the second bank handled differently at the controller level? Does this code work better in the last sector of the first bank?

Add some diagnostic output so you are not fighting with the debugger.