MON51: Conflict Between Data And Code Memory

Information in this article applies to:

• C51

SYMPTOMS

I have read in the MON51.HLP file that in order for the Monitor to function correctly the data and code memory have to be von Neumann wired so that they occupy the same physical memory locations. Looking at my map file it appears that both data and code memory start at location 0000H, however my program executes on my target board with the Monitor. How is this possible?

CAUSE

The data memory is internal and is either 128 or 256 bytes in size. This memory space is completely seperate from any external memory or internal code memory. It is xdata and code memory that has to be von Neumann wired, and the possible conflict is between these two memory areas. xdata is the external data memory.

SEE ALSO

• MON51: Testing Von Neumann Memory Areas
• MON51: Configuring for Target

Last Reviewed: Thursday, February 25, 2021