XDATA corruption from user_flash_read /_write

Question

XDATA around 0x42A6 is being corrupted during user_flash_read(), user_flash_write(), setSIPR(), setGAR(), setSUBR(), or setSHAR(). Presumably during do_isp(), which user_flash_* calls. This was overwriting a 2-byte array “byte foo[2]={0xff,0xff};” with 0x00, 0x00. I masked the problem by moving variables to DATA from XDATA, but need to understand the root cause. Any thoughts?

irina · Answer

I’ll check this issue from the person in charge. Please understand that there will be a delay in response due to the Christmas, and New Year holidays. Thank you for your patience and we will get back to your questions ASAP. Sincerely,

irina · Answer

I wish you would change the Memory Model as “Large: variables in XDATA” in target tab of option. image737×435 12.2 KB And when you changed the mode, I want to know if the same issue occurs. Could you please you send me your project if it is possible to send project?

irina · Answer

In my private opinion,I want you don’t use the standard printf function. I suspect that the stack is broken because of the printf function. So, I recommend that you don’t use the printf function and try again. Reference link for printf(C51): C51: WHY NUMBER OF BYTES PASSED TO PRINTF IS LIMITED