Advice on Logic Analyzer

Interesting to had seen what jumped out in this conversation, all the finer nuances :) Bob was right, times are changing

It seems that Janatek, the company that manufactures the Annie-USB and Logic-16 has been around for some time. What I also like about the Annie-USB is that it is also a pattern generator. These things cost some money if you buy it separate. Anyway I came across an article on their website that eloborate on which aspects you should consider when comparing pc based logic analyzers.

The rocky's also seems to me worth considering

It's faster and cheaper to analyze your logic before you build it.

John

Well to be fair, nobody's usually dumb enough to want to sample an entire screen full of RGBI data, usually you just use a RGBI monitor for that! Looking at one line is usually enough. Except when you interlace the display, and the physically "next" line on the screen is an entire vsync time away. Of course you could program the triggers to ignore the rest of the field but now I don't remember if you could do that with the Logicport.

You know, it is spring cleaning time here in the northern hemisphere. Maybe I'll put my logicport up for sale, since I haven't used it in a year and that's an important criteria in the cleaning.

But what if you're analyzing someone else's design from twenty years ago and there's no documentation? Sometimes a new design has to work with old stuff. I wonder if there's a logic analyzer with enough input range to handle the logic levels inside a 6R1A?

That depends on what you want to do with your data. I don't know about the Janatek LA, but my own LA (a tektronix DAS9200) allows to read the acquisition memory into the PC for automated analysis or drawing pretty pictures on the screen based on the data.

On Apr 15, 9:52=A0am, John Larkin

That's small company talk for sure!

A large company has vastly different day to day problems that what you normally experience.

Yup. The more people you put on a project, the less they understand.

John

Statements like these make me wonder if I should give Modelsim a try... Still, the thought of having to create a testbench doesn't appeal to me. Especially for a design that has a massive amount of configuration registers. Anyway, it all boils down to verifying your design one way or another.

And get an unsupported piece of equipment to start with for which getting spare parts is a matter of pure luck? I own an old & bulky Tek LA myself, but with today's prices for USB logic analyzers I might choose differently if I have to replace it.

Yup. Design-by-committee never works.

The Girl Scouts are heading that way... combining neighborhoods so we're looking at managing 1000's of girls rather than 100's... with all functions "by committee".

My wife just outfoxed them and designated herself as Registrar and me as the Committee ;-)

...Jim Thompson

There not really unsupported, only by the manafacturer. As for parts there is so much and so cheap you dont need much luck. They dont go wrong often either as they were well made in the first place. And of course they are repairable unlike your USB jobbie.

The reason that Logicport will not soon be coming out with a follow- on product with more sample memory is stated in an article published recently on Evaluation Engineering: Quote The LA1034's logic and memory are entirely contained within a single FPGA," commented Harrison Young III, company CEO. "This keeps the speed up and the cost down compared with products having external memory interfaces. The LA1034's efficient lossless compression algorithm allows its buffer depth to be greatly extended with no loss in signal integrity." The small sample buffer available in the Logicport is that which is available within the mentioned single FPGA, if they should bring out anything with a slightly larger internal memory, they would have to redesign the whole instrument. Also data compression works in certain cases, but certainly is no magic. Otherwise every company would have offered it, since it saves a lot of development and manufacturing costs.

Isn't that what any PC-based logic analyzer do in principle? Capture the data and then relay it to its software on your pc for 'pretty pictures' :) What I like about that compared to standalone LA's is the inherent mobility it creates. You can move about with your analyzer and keep the captured data on your flash. Most of these programs can export the captured waveforms to a CSV, text or bitmap file that you can e-mail or compare. If you have some time, go download their demostration software or another manufacturers.

I'm pretty convinced to go for a pc based rather than standalone, maybe jump with me?

Yup. And FPGAs keep getting wider, deeper, and faster, so I'd expect a follow-on.

Well, yeah, but that's the beauty of HDLs innit?. It's not like they'd have to respin from, say, a discrete transistor layout to logic gates.

Once again, there is no universal, single best solution. For my part, I've used PC-based analyzers with each approach and find that the transitional sampling technique in the LogicPort is the better fit.

One notes that Janatek's mailing address is Stellenbosch, Western-Cape, South-Africa.

One notes that, in contrast to the "yahoo.co.UK" e-mail address, the actual posting IP is 198.54.202.254, which is a .za (South Africa) domain with a Western Cape contact address.

Gentlemen, I think we have a sock puppet.

Data storage is standard, usually on disk, most have printer outputs as well.

Most of these programs can

Are you likely to want to email your data?

If you have some time, go download their

Maybe you report back how you get on with it.

No, it is very nice to be able to have an LA with an API or protocol with which you can read the data into your own application.

I disagree, design-by-committee works more often then not. A guy in his garage will product a vastly superior product if he doesn't give up, run out of money, run into health problems etc etc. A large company is mostly immune to those issues, it may produce crap, but at least it's making and selling something!

I bought a DigiView LA made by

Data can be exported and triggering is adequate. Its portable and I travel all over the country with it to client facilities. It won't match a benchtop model in performance, but it's been great for that portability and light - moderate use. Like most of these type products - the tiny spring clips are pretty delicate, but they can grab SMD parts.

Steve