Input clock trigger ?

[Alexis]

Hi,

I have a Analog Discovery the black version (first one?!) and I would like to do a simple logic analysis.

I have a clock signal (20MHz) and some other signals.

I would like to trigger the analysis (get the value of the signals) at the rising edge of this clock.

I didn't find anything...

I am using the Waveforms 2015 v.3.2.6.

Thank you very much.

[attila]

The trigger can be specified in the Logic Analyzer for each added signal in the Trigger ('T') column, default is Ignore ('X'). 

[Alexis]

Thank you but I don't understand...

I can choose rising or falling edge but I cannot choose the "clock" signal.

I want to D-flip-flop every signals by using one clock signal. As a common logic analyzer does.

Thank you, nothing is clear in the software.

[attila]

In case you want to use external clock, this is not supported.
You can add Bus interpreter with optional Enable and Clock signal.

[dasboos]

EDIT**  I am using the Scope function but I see a similarity in his question to a question I have**  I think what he is trying to ask, is "how can I make it so the screen captures (stops) when my clock signal is used as a trigger"?  I am wondering the same thing, I just bought one of these and I can accept that there is a learning curve, but I really should be able to easily set a trigger, then connect the probes to say, a battery or something, and be able to capture the rising voltage event to the screen.  This is pretty standard stuff on any scope/logic analysis device I have ever used, and I am struggling with this, poking at menus and trying various things.  So far even if I set it to SINGLE it is a bit unintuitive, by the time I get to the probes to connect them, the 'single event' cycle has already expired (even though the event that should have started the 'single' never occurred- a rising edge that hits the trigger level) So I then put the time base to something slow like 1S per division, then if I move really fast I can now connect my battery, wait for a few more seconds, then see the fun event appear on the screen. This cannot possibly be the intended method for capturing a single rising edge event, I am betting the OP would have a hard time doing this with his 20MHz clock pulse.  But as I said, so far the software is non-intuitive, can someone please, describe to me how I can capture any particular trigger event and have it persist on the screen, so that I might analyze other probes' values at that moment-- I think that might help the OP also....

[lengland]

Hi dasboos,

I referenced the help menu in the waveform program. The first step to setting the trigger would be to click on the green arrow on the right side of the window next to the voltage drop down window. That will show more options. You need to make sure the  mode is switched to normal. The condition should be set to rising so that you are using a rising edge as a trigger. Setting the type option to edge will allow you to set the trigger condition to be on either the rising or falling edge. Next you need to adjust the level. This option is so that when the event reaches that voltage it will start the acquisition event. Please note that the Hyst option is the hysteresis. This will affect the level. The auto option uses 1% of the specified trigger channel range value. Using the Single option will allow you to capture the even you want.

If you have more question I would recommend the help menu or comment back. I would be happy to help.

 

-lengland

[lengland]

Hi Alexis,

To do logic analysis, I would recommend using the Logic option in the Welcome tab. There you can add channels and pick the type you want. Once you have picked the type you want you can change the trigger type by clicking on the T and changing it to the desired trigger type, as attila stated.

If you have more question the help menu is very useful.

-lengland