If you just get “??” marks, then the memory map access transaction could not complete correctly on the transaction level, so there is no data to report back.
If the access should succeed then the typical cause is bad mapping of such a memory area in local access windows so that no one to respond can be reached with the read access.
Note that waiting for such transactions can take time, depending on system configuration. So it is better for effective debugging to either have a fully mapped system, or to consider using CodeWarrior memory configuration files to tell the debugger which memory areas are “off limits”.
If you just get “??” marks, then the memory map access transaction could not complete correctly on the transaction level, so there is no data to report back.
If the access should succeed then the typical cause is bad mapping of such a memory area in local access windows so that no one to respond can be reached with the read access.
Note that waiting for such transactions can take time, depending on system configuration. So it is better for effective debugging to either have a fully mapped system, or to consider using CodeWarrior memory configuration files to tell the debugger which memory areas are “off limits”.