We have been having problems with accidently activating CSM and therefore being permanently lockout out. Probably due to some sort of interruption during flash erase / program, which we may have sorted out following a previous question to this forum. However, we are worried about it happening again.
I have been told that a way out used by some people is to load a flash erase program to OTP. Thus selecting boot to OTP erases all flash, unlocking the processor. I have looked at this, loading to flash as a trial, and it seems to work (code is copied to RAM and erases flash sectors). However, I can’t write a program small enough to fit in the OTP. OTP is 0x400 words, and the Flash API alone is larger than this, even calling only Flash28335_Erase. (pdf in sprc539.zip suggests 0x43f.)
So, what was used. Is there something I can load to OTP that will simply erase all flash?