MSO/DSO oscilloscope as logic analyzer

[bobwidlar]

Dear all,

I've been trying to measure the ADC I designed, and I would like to capture 3-bit digital data @ 25MHz via an oscilloscope. Currently I have Agilent DSO 3054A available. The problem is,  I couldn't find a way to synchronize the data to the clock of 25MHz I'm providing on the CLK line of the digital inputs. A normal logic analyzer would do this, but is it impossible with the oscilloscopes?

[nctnico]

AFAIK there are MSO oscilloscopes with external clock inputs but they are very rare. You'll have better luck with a real logic analyser.

[tautech]

Dear all,

I've been trying to measure the ADC I designed, and I would like to capture 3-bit digital data @ 25MHz via an oscilloscope. Currently I have Agilent DSO 3054A available. The problem is,  I couldn't find a way to synchronize the data to the clock of 25MHz I'm providing on the CLK line of the digital inputs. A normal logic analyzer would do this, but is it impossible with the oscilloscopes?

Can't you do that with the analogue inputs? 
Then the full trigger suite available can be used.

Did you watch Dave's recent vid where he's looking at a bus with his Agilent DSO?
https://www.eevblog.com/forum/blog/eevblog-879-rs-1202-scope-bandwidth-hack-investigation/

[rstofer]

most of the time, I have to invent a trigger pulse.  My projects tend to revolve around uCs or FPGAs so it is usually possible to output a synch pulse some time before things get interesting.

[2x2l]

Dear all,

I've been trying to measure the ADC I designed, and I would like to capture 3-bit digital data @ 25MHz via an oscilloscope. Currently I have Agilent DSO 3054A available. The problem is,  I couldn't find a way to synchronize the data to the clock of 25MHz I'm providing on the CLK line of the digital inputs. A normal logic analyzer would do this, but is it impossible with the oscilloscopes?

Can't you do that with the analogue inputs? 
Then the full trigger suite available can be used.

Did you watch Dave's recent vid where he's looking at a bus with his Agilent DSO?
https://www.eevblog.com/forum/blog/eevblog-879-rs-1202-scope-bandwidth-hack-investigation/

I skipped to about 15 minutes in just because I wanted to see what sort of visualization software he was going to use off that hack (I've never seen R&S' protocol analyzer software and I wanted to see how similar it was to the "Gold Standard" (at least in my mind,) Teledyne). Instead I saw a deformed chip with half of the wafers protective layer had been killed. Did he take fuming nitric acid to it or something?!

[bobwidlar]

AFAIK there are MSO oscilloscopes with external clock inputs but they are very rare. You'll have better luck with a real logic analyser.

Well, the one I have has a CLK input but only active on protocol decoding mode.

I can give it a trigger, actually I can use digital lines as trigger too (assuming acquisition trigger?). But the problem is the internal clock and the ADC's clock are not synchronized. You see a big bit error rate if the both sampling frequencies get close as expected. I want to get like 4 million data points, so I want to use the oscilloscope sampling as close as to ADC's Fs for maximum data rate. I didn't try to sync both clocks with external trigger in though.

[nctnico]

How about getting a long record, save it to disk and post-process it with PC software?