Heiko Buhr

Building a Checksum with paged ROM

Discussion created by Heiko Buhr on Jul 9, 2008
Latest reply on Jul 14, 2008 by David Kelly
I need help concerning the following:
I have to build a CRC32-Checksum of the whole FlashRom and parts of the EEP of a MC9S12DP256. The problem is: the memory is configured as "paged", so I have to use the PPAGE - register. Unfortunately the code is located on Page 38, which is not a fixed adress page. Therefor when I use the PPAGE register, the controller runs anywhere.
Is there any solution how to read the ROM by using a pointer from any page or is the only way to locate the code on a fixed adress page? This would be very difficult because these pages are nerly completely full with data, tables, flashbootloader, Lib's, ...
Hope someone can help me.