My first guess is that the MMU (Memory Management Unit) has not been configured to define this failing address space as valid. Check your Chip Select, BAT and TLB registers to make sure they're correct. Also, while the debugger is running, open a Memory window (Data->View Memory) on 0x1003600 (or similar) address and see if you can manually poke new values into this RAM. And finally, I recommend creating a Memory Configuration file (selected in the 'EPPC Debugger Settings' panel of your CodeWarrior project) to declare the valid and invalid memory spaces in your target's memory map. This helps the debugger understand what memory spaces are valid and invalid, and the properties (bus-width, address-translations, etc.) associated with each block of addresses. Details on the 'Memory Configuration' file are found in the "Targeting Manual" in your CodeWarrior's /Help folder.
And it's always a good idea to have valid Exception Handler code for every Exception defined for the Power Architecture processor you're debugging. These Exception Handler routines don't have to do anything more than have a few NOPs and an RTI. The purpose here is to avoid the processor throwing an Invalid Instruction Exception when it tries to fetch the first Exception Handler instruction, thereby avoiding an unnecessary complication when drilling into the underlying cause of what might be going wrong on your target board.
