The Watchpoints system view, shown in Figure 5.80, enables you to set, modify, or remove watchpoints. You can change the column widths by dragging the dividing lines between the column headings to the left or right.

Figure 5.80. Watchpoints system view

You can see details of any watchpoints that are currently set. To disable an existing watchpoint, click the green disc at the left of its line. The center of the disc becomes gray. Click the disc again to restore normal operation. A disc has a red cross through it if the watchpoint is currently out of scope.

To add a new watchpoint, right-click anywhere within the Watchpoints system view to display the pop-up menu shown in Figure 5.81 and select Add.

To modify a watchpoint, do either of the following:

Figure 5.81. Watchpoints system view pop-up menu

The Locate Using Address menu item functions as described in Watch processor view pop-up menu.

Select Refresh to update and recalculate the displayed data values. This item is useful if the target supports RealMonitor. See also Refresh All.

Whether you are adding a new watchpoint or modifying an existing watchpoint, you use the Watchpoint Properties dialog shown in Figure 5.82.

Figure 5.82. Watchpoint Properties dialog

The fields in the Watch group specify the location of the watched value. The Processor field enables you to select one processor if your target has multiple processors. Specify in the Item field what to watch by giving the name of a variable or register, or an expression that evaluates to an address. The Watching field is read-only.

The fields in the Condition group enable you to specify when a change in the watched value must be ignored and when it must trigger the watchpoint. You can specify in the Value field a numeric constant, in which case the watchpoint is triggered only if the watched value changes to the specified value. You can specify in the out of field the number of times the watched value must change to trigger the watchpoint. Also, if you specify an expression in the when field, changes in value are counted only if the expression evaluates to True. You can concatenate conditions by using the C language && and || syntax.

Under Status, you can see whether the watchpoint is currently enabled, and change this setting if required. You can also see whether it is a software or hardware watchpoint. A hardware watchpoint can have a hardware resource identifier.

Under Size, you are recommended to leave Force Size unchecked. The area of memory watched is then the size of the variable if you are watching a variable, or a 4-byte word if you are watching a memory location. If you force the size of the watched area of memory you can select 8, 16, or 32 bits.

The setting in the Action group is normally Break, to stop execution when the specified conditions are met. The alternative, Log, adds a record in a log of events. If you select Log, whatever you enter in the Text field is output each time the conditions are met. To examine the log of events, select Output from the System Views menu (see Output system view). The pop-up menu of the Output system view enables you to save subsequent records in a disk file and to clear the current entries from the log.