SP Lee

Protected memory - Bootloader for MC9S08JM32

Discussion created by SP Lee on Jan 11, 2011
Latest reply on Jan 11, 2011 by kef

I have a MC9S08JM board which already has code programmed into it - the code includes bootloader and user application program. The program memory section 0XF6FF - 0XFFFF is protected (using the NVPROT/FPROT registers) - this is where the bootloader resides.

Now, I want to change the user application program (which is located in program memory other than the protected area). I have a VC++ program which will download a *.hex file into the MC9S08JM32 throught USB cable (the bootloader code uses USB). The VC++ doesn't care (it doesn't know either) that there is a protected area in the MC9S08.

What happens if the VC++ attempts to flash the entire program memory, including the protected memory?