Forum Discussion
New ContributorSignal Tap false trigger
I'm using Quartus Signal Tap to capture waveforms and encountering a false triggering issue (triggering when the trigger condition is not met, for example, trying to capture the moment when a signal that is constantly low becomes high, but it captures incorrectly). When this false trigger occurs, only half of the waveform is displayed (only the waveform after the trigger position). Has anyone experienced a similar problem? How can this be resolved? (Agilex 7 using HPS)
11 Replies
KennyT_alteraSuper Contributor
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- xiaohao
Thank you. I think I've found a possible reason related to the HPS debug settings, but I'm not sure why yet
FvMHi,
a popular reason for experiencing "false trigger" or incorrectly acquired signals is tapping signals that are asynchronous to signal tap acquisition clock. Respective signals usually generate timing failure in timing analysis.
Seeing no data before trigger event simply means that trigger condition is immediately met.
Regard
Frank
- xiaohao
I temporarily resolved this issue by disabling the hps debug port. Please see the image below.
Based on my experience, even with immediate triggering, all waveforms should be displayed. For example, if I set all conditions to "don't care," it triggers immediately, but the captured waveform is different from what I described.
- sstrell
At the bottom of the Signal Configuration section of Signal Tap, did you have the Trigger In feature enabled using the DAP as the source? That might partially explain this.
- sstrell
It is odd to not see any post trigger data like that without a storage qualifier enabled.
What are you using as the acquisition clock? Is your design meeting timing as suggested above?
