To toggle a flag with the mouse, double-click the flag.The Register window displays the names and current values of the native CPU registers and flags. When you are debugging p-code, it displays names and values of the p-code registers and flags. You can change the value of any register or flag directly in the Register window.
To open the Register window, choose Register from the Windows menu, press ALT+7, or F2. You can also view and modify registers by using the Register (R) command. For more information about the Register command, see page 450.
When a register value changes after a program step or trace, CodeView highlights the new value so you can see how your program uses the CPU registers. Depending on the current instruction, the Register window also displays the effective address at the bottom of the window. This display shows the location of an operand in physical memory and its value.
If you are debugging on an 80386 or 80486 machine, you can view and modify the 32-bit registers. To turn on the 32-bit Registers option, choose the 386 command from the Options menu or use the O3+ command. The 32-bit registers are available if you are debugging on an 80386 or 80486 machine.
When you are debugging p-code, CodeView displays the p-code registers: DS, SS, CS, IP, SP, BP, PQ, TH, and TL.
If your program has taken an unexpected turn, you may be able to compensate for the problem and continue debugging if you change the value of a register or a flag. You can change a flag value before a dump or looping instruction to test a different branch of code, for example. You can change the instruction pointer (CS:IP) to jump to any code in your program or to execute code you have assembled elsewhere in memory.
To change the value of any register, move the cursor to the register value you want to change and overtype the old value with the new value. The cursor automatically moves to the next register.
Although you cannot change the value of the flag register numerically in the Register window, you can conveniently toggle the values of each flag using either the mouse or the keyboard:
To toggle a flag with the mouse, double-click the flag.
To toggle a flag using the keyboard, move the cursor to the flag and press any key except ENTER, TAB, or ESC. After toggling a flag, CodeView moves the cursor to the next flag.
To restore the value of the last flag or register that you changed, choose Undo from the Edit menu or press ALT+BACKSPACE. If you happen to lose the cursor somewhere in the register window, press TAB. The TAB key moves the cursor to the next register or flag that can be changed.