7.1.1. Displaying register contents

To examine the contents of registers:

  1. Connect to your target and load an image, for example dhrystone.axf.

  2. Select View → Pane Views → Registers to display the Register pane and bring the Core tab to the front.

  3. Click on the Src tab to view the source file dhry_1.c.

  4. Set a simple breakpoint by double-clicking on line 150.

  5. Click Go to start execution.

  6. Enter 5000 when asked for the number of runs.

    The program starts and then stops when execution reaches the breakpoint at line 150. The red box marks the location of the PC when execution stops.

  7. The contents of the Register pane are updated to show the program status as the target stops, shown in Figure 7.1.

    Figure 7.1. Register pane

    Register pane

    The Register pane displays tabs appropriate to the target processor running your image and the execution vehicle. Different target processors contain different registers and so the contents of this pane change depending on the target you are debugging.


    If your target processor is configured using .bcd files, additional tabs are also shown. Figure 7.1 shows the MCUeval tab, but the name of this tab depends on your specific debug target.

  8. Click High-level Step Into to execute one instruction and then stop. Register values that have changed, since the last update, are displayed in dark blue.

  9. Click High-level Step Into a few more times and examine the register values as they change.

  10. Right-click on a changed register and select View Memory At Value to use the chosen value as the starting address for a memory display.

    This displays the memory view in the last-used Memory pane. If a memory view is not visible, the default Memory pane, in the middle pane row, is used to display the view.

  11. Monitor changes in the Register pane as you step through your program.

  12. Double-click on the red marker disc to clear the breakpoint at line 150.

Display colors

When using the Register pane to view register contents, RealView Debugger uses color to make the display easier to read and to highlight significant events:

  • Black indicates values that are unchanged for the previous two updates.

  • Dark blue shows those values that have changed since the last update.

  • Light blue indicates a value that changed at the previous update.

Copyright © 2003, 2004 ARM Limited. All rights reserved.ARM DUI 0234B