RealView Debugger User Guide - ARM Information Center

Working with BreakpointsFor full details on using RTOS extensions and running in RSD mode, see the chapterthat describes RTOS support in RealView Debugger v1.8 Extensions User Guide.4.1.8 Using hardware breakpointsSetting a software breakpoint requires that the debugger changes executableinstructions, so this is only possible for code stored in RAM. Where instructions are inFlash or ROM, you must set hardware breakpoints.The number of hardware breakpoints available depends on your debug target. IfRealView Debugger cannot set breakpoints, a warning message is displayed and rapidinstruction step is used for high-level stepping. Again, a warning message is displayedto explain the type of step being used.Be aware of the following when working with hardware breakpoints with RealViewARMulator ® ISS (RVISS):• Watchpoints are available. These are called hardware breakpoints in RealViewDebugger. You can access them through the Debug → Breakpoints →Hardware menu. These data access breakpoints are implemented using amemory hook.• Hardware breakpoints can use address ranges (see Specifying address ranges onpage 4-7), data values, and data value range tests. They can also include size tests,mode tests, and pass counts.• Hardware breakpoints can be chained to form complex tests.To use hardware breakpoints, your debug target must include support for suchbreakpoints. Even where this support is available, your target might be limited in thenumber it can support at one time. RealView Debugger menu options related tohardware breakpoints are grayed out if your target cannot support them or if no moreare available.Viewing your hardware breakpoint supportTo see your hardware support for breakpoints, select the following option from the Codewindow main menu:Debug → Breakpoints → Hardware → Show Break Capabilities of HW...This displays an information box describing the support available for your targetprocessor, shown in Figure 4-2.ARM DUI 0153G Copyright © 2002-2005 ARM Limited. All rights reserved. 4-13