Ronald Weaver

MCF52258:  writing to internal flash

Discussion created by Ronald Weaver on Oct 25, 2011
Latest reply on Oct 25, 2011 by Mark Butcher

The MCF52258/9 Coldfire processor has 512 kBytes of  internal 32 bit flash.  In our design we have divided the 512 kBytes into blocks for specific purposes.  We have allocated 64 kBytes for a boot-loader, two blocks of 32 kBytes for non-volatile persist memory, and two blocks for two copies of the firmware. One copy of firmware runs while newer code can be downloaded to the other block.


So the requirement is to be able to erase a section of flash memory and be able to write new data or code to the section that was  erased.  I would think this would be common firmware design.


I've read the MCF52259 Coldfire reference manual on this topic.  The logical page erase procedure in the manual is understandable, although it would be nice to provide examples.  However, the flash program example and information is not straigthforward.  I'm confused by the mention of a backdoor flash address with little information on it.  Plus there is no direct #define definition for this important address in any of the ".h" files.


I would really appreciate any help with clues and examples in this effort.


Best Regards