[Modelsim FAQ] How to add submodule signals to the waveform window for observation

小梅哥

[Modelsim FAQ] How to add submodule signals to the waveform window for observation [Copy link]

 

When debugging, you often need to check some signals inside the module under test or even the signals inside multiple submodules instantiated in the module under test to find the cause of the problem. At this time, you can manually add the signals of these modules to the waveform window. Take
the I2C controller project written by Xiao Meige as an example:
1. First, run the simulation according to the normal process, then the waveform window will automatically add all the signals in the testbench and display the waveform, as shown in Figure 1
(Warm reminder, the picture size is relatively large, click the picture to view the high-definition picture)

2. In the sim column, select the module you want to observe, then right-click and select add wave to add all the signals in the module to the waveform interface. As shown in Figure 2.
(Warm reminder, the image size is relatively large, click the image to view the high-definition image)

3. If you only want to add some of the signals you are interested in in this module, you can first select the module with the left mouse button, then select the signal you want to observe in the Objects window on the right (yes, the window with a dark blue background), then right-click and select the add wave button, as shown in Figure 3.
(Warm reminder, the image size is relatively large, click on the image to view the high-definition image)

4. The signal after adding is shown in Figure 4. You can see that after adding, the signal exists, but there is no waveform.
(Warm reminder, the image size is relatively large, click on the image to view the high-definition image)

5. Click the "restart" -> "Run -all" buttons in sequence to restart the simulation, and all signals will have waveforms. See Figure 5.
(Warm reminder, the image size is relatively large, click the image to view the high-definition image)

6. If the signal name is too long to be seen clearly, click the Hide/Show Hierarchical Path button in the lower left corner to open/close the hierarchical path and only display the signal name. As shown in Figure 6
(Warm reminder, the image size is relatively large, click the image to view the high-definition image)

7. If all signals are superimposed together and you don’t know which module they belong to, you can use the shortcut keys "ctrl + a" -> "ctrl + g" to quickly group the signals belonging to each module.

If it is well written, please give Brother Xiaomei a thumbs up.