Ian Murphy

Problem accessing 9S12XEP100 memory region 0x5000->0x7FFF

Discussion created by Ian Murphy on Sep 27, 2011
Latest reply on Sep 28, 2011 by kef



According to the reference manual (page 35), memory region 0x4000->0x7FFF of the 9S12XEP100 is Unpaged FLASH. I am using the region 0x5000->0x7FFF to store 'const' read-only data.


The memory region is programmed OK by the BDM, along with the code which is in 0xC000->0xFFFF. When the processor is reset the debugger shows the region 0x5000->0x7FFF is filled with the right values.


But, if the software is started then halted, the region 0x5000->0x7FFF shows different (wrong) values.


What could be causing this? The software uses the small memory model and I thought in this memory model 0x4000->0x7FFF will always access the same region as it's an un-paged area?


Thanks, Ian