Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

6.2.2.2. Watchpoints

Watchpoints provide a powerful method to capture all writes to a global variable that appears to be corrupted. The Nios® II Software Build Tools for Eclipse support watchpoints directly.

For more information about watchpoints, refer to the Nios® II online Help. In Nios® II Software Build Tools for Eclipse, on the Help menu, click Search. In the search field, type watchpoint, and select the topic Adding watchpoints.

To enable watchpoints, you must configure the Nios® II processor’s debug level in Platform Designer to debug level 2 or higher. To configure the Nios® II processor’s debug level in Platform Designer to the appropriate level, perform the following steps:

  1. On the Platform Designer System Contents tab, right-click the desired Nios® II processor component. A list of options appears.
  2. On the list, click Edit. The Nios® II processor configuration page appears.
  3. Click the JTAG Debug Module tab, shown in Figure 244
  4. Select Level 2, Level 3, or Level 4.
  5. Click Finish.

Depending on the debug level you select, a maximum of four watchpoints, or data triggers, are available. Figure 244 shows the number of data triggers available for each debug level. The higher your debug level, the more logic resources you use on the FPGA.

For more information about the Nios® II processor debug levels, refer to the Instantiating the Nios® II Processor chapter in the Nios® II Gen2 Processor Reference Handbook.