Flash not working during the writing cycle in stm32f103CBT6!

Hi All,

I'v been working on a project wherein I use some portion of the flash to store certain data. Initially, after the manufacturing and assembly procedure, I don't usually get any issues at all, but after several months, the board starting to give random issues whenever I try to write any data into the flash memory.

When I run the code into the debug mode, I noticed, the moment my code execute the "FLASH->CR|= CR_STRT_Set" in the "FLASH_ErasePage" function, complete sector of 1KB gets corrupted.

On the other hand, I'm able to modify the same location (which were giving issues) via ST-link.

I would also like to know, what is the maximum limit (Number of write cycles) of internal flash write?