Debugging Techniques
- Updated2025-10-09
- 2 minute(s) read
To interactively debug patterns on digital pattern instruments, you typically pause the execution of the test program and open a project in the Digital Pattern Editor that has the same active pin and channel map as the test program uses. If you previously created instrument sessions with the digital pattern editor, disconnect those sessions before executing the test program. The digital pattern editor automatically connects to the available instruments defined in the active pin and channel map or returns a detailed error message explaining why it cannot connect to the sessions. You can also select the menu item in the digital pattern editor to connect to the existing instrument sessions the test program application created.
- Use the System View to view or modify pin settings and measurements.
- Use the Pin View pane to view or modify pin settings.
- Unload, load, and burst patterns after optionally modifying specifications, levels, timing, or pattern components.
- View History RAM results for bursts in overlay mode in pattern documents or in the History RAM View. Use the Instrument Settings pane to customize settings for logging results to History RAM.
- Mask pins to ignore failures in a pattern burst for those pins.
- Disable the sites you want to ignore while debugging.
- Execute Shmoo or digital scope operations to review results.
Related Information
- System View
Use System View to edit settings and measurements for pins and relays. This applies to an active pin and an active channel map connected to a digital pattern instrument, NI-DCPower instrument, or relay driver module.
- Pin View Pane
Use the Pin View pane during debugging to interactively view and modify the current state of the pin driver, active load, comparators, PPMU, and NI-DCPower instrument settings for a single pin at a time in the active instrument session.
- Bursting Patterns and Viewing Results
- History RAM View
Use this view to see the History RAM results for the flow of pattern execution for the last pattern burst across all executed patterns for the number of samples you specify in the Instrument Settings pane, including vectors with repeat opcodes. The view also includes the corresponding time sets, labels, opcodes, pattern names, vectors/cycles, pin state data, and comments. Rebursting a pattern overwrites the data in the History RAM View.
- Instrument Settings Pane
Select Instrument Settings History RAM and Signal Settings to launch the Instrument Settings pane.
- Masking Compares on Pins or Pin Groups
In the pattern document, select cells in the columns for the pins or pin groups for which you want the digital pattern instrument to ignore failures when you burst the pattern, right-click, and select Mask Compares on Selected Pins from the context menu. Select cells in the columns for masked pins or pin groups, right-click, and select Unmask Compares on Selected Pins from the context menu to remove the setting. These settings persist only until you close the instrument sessions.
- Shmoo Plot
Use the Shmoo plot to view a dynamically updated plot of pass and fail values for a sweep of up to two variables you specify using the specifications, timing, levels, pin and channel map, and pattern files in the project. An asterisk (*) next to a filename in the Project Explorer window and in the document tab indicates that the file has been modified but not saved.
- Digital Scope
Use the digital scope to view a graph of the expected waveform underneath the actual waveform using the pattern, timing set, and levels, including compare strobe locations, VOH and VOL levels, and expected drive levels. You can use the digital scope to help debug failures to verify that the actual waveform accurately reflects what you expect based on what the pattern and timing define.