DDiscovery - missing first 8 samples on sync mode

[hlipka]

I'm using the sync mode, triggered by the pattern generator. My config is one 14 bit counter (DIO24-DIO37), and a clock on a single signal (DIO38). The logic analyzer is configured to sample DIN0-DIN7 on the rising flank of DIO20 (which I connected to DIO38). But I'm missing the first 8 samples. How do I know? The device-under-test is a ROM and I already know its contents. I actually get the correct values when the counter on the pattern generator wrap around and starts again. I verified with a scope that the generated pattern is correct (so the sample clock starts at the correct time). Is this a bug in WaveForms or do I need to configure some special?

(On that note: it would be nice when I could restrict the pattern generator to one single run on the counter instead of being time-based)

[attila]

Hi @hlipka

To overcome this problem do not let the Logic Analyzer Sync more to finish. For instance set in Patterns a finite run, to have less clock cycles than configured samples for sync and stop it by pressing cancel.
This bug will be solved by the next software version.

Instead single we could add an auto run length, which based on configured signals could calculate the run length, similar to Wavegen "Auto synchronization" mode.

Sorry for this issue and thank you for the note.

[hlipka]

Thanks for your response. Is there anyway in the Pattern Generator to specify the number of clock cycles? I can see only a time-based limit.

 

Thanks,

hli

[attila]

Hi @hlipka

The number of cycles can be limited specifying a finite run time and repeat once.