Jesper Hæe

S08 - does the backdoor key enable erase and write access to block protected sectors?

Discussion created by Jesper Hæe on Apr 18, 2007
Latest reply on Apr 19, 2007 by David Payne

I have been reading the reference manual and a lot of post on this forum, however it is still very unclear to me if the backdoor key only unlocks the read secured FLASH or if it also unlocks the block protected flash. Enabling erase and reprogramming of the top sectors.

If the backdoor key does not unlock the block protect? Is there another way to do this from the application?

The scenario for which I potential need this feature is this: we have a product (HCS08GT60 based) with a functional bootloader, this bootloader is block protected and takes 2kB of the code space. However due to increasing demand for functionality, the application needs more space. To meet the demand we are considering if it is possible to change the bootloader to a version based on the an2295. For this to work it would be necessary to be able to load an application that could unlock the protected flash and erase it and load a new bootloader and a new size for the protected sectors.