Dear all, when i write 0xfe into HCR0 register using startup.a51 my program works fine.. whereas when i wanted to write into program memory i have to enable PML bit. ie i wrote 0xbe into HCR register.My program gets reset again and again .. I thought this might be problem with watchdog timer and disabled it in the same register (writing 0xb6 ). Now there is no Response from the program what is the issue??? can any expert help me in this ??