Data breakpoint is a breakpoint that be triggered when the content of a specified memory location is modified.

In a complex program, to find where and when a specific variable was modified may be difficult.

In this scenario, step through the source is almost impossible and there is no place in source code you can set breakpoint. You have no idea which part of the program changed the memory.

The solution is data breakpoint.

Press Alt + F9 open breakpoint window. Select "Create Data Breakpoint". You need the memory address to break on and number of bytes start from the address.

To get address of a variable, go to command window and query.

? &var

This command will display the memory address of variable .

If the variable is boolean, the number of bytes should be 1 byte, if its a integer, the length should be 4.