Some NOR flash have the protection&unprotection mechanism. On power up, all blocks in the device are protected. If we want to access the protected block, the Abort could be happen. To unprotect the a block, we must write the block protection/unprotection command sequence as the following:
wptr[0] = 0xF0;
wptr[0] = 0x60;
wptr[0] = 0x60;
wptr[0x42] = 0x60;
But i don't know the meaning of the digit 0x42. Who can tell me?