Products > Test Equipment

Which logic analyzer for FPGA work up to 300-400 Mhz

(1/11) > >>

suspension:
I do quite a lot of FPGA work and use internal chip scope from Xilinx to inspect internal signals. The biggest issue with this approach is that any change requires a re-synthesis/implementation of the design which can take 5-15 minutes for complex designs. Therefore, I am evaluating a dedicated logic analyzer with good trigger capabilities and some support for protocol decoding.
My budget is 500USD. Used ones are OK.
Two main options are either to buy a used old HP/Agilent/Tek from ebay or buy a new USB based one from ebay/Amazon/Aliexpress. I prefer the first option but wanted to check others' opinions as well. Thoughts?

nctnico:
I'd get an old Tektronix like the TLA700 series (TLA715 for example). The triggering abilities on these are awesome and they have 56 bit timestamps on all samples so you can use an acquisition mode that only records where certain signals change allowing for really long recordings without wasting memory on useless information. In most cases I don't bother to setup a specific trigger.

IMHO the TLA7AA4 acquisition modules are the nicest option because there also have 4 analog outputs that allow to watch any connected signal using an oscilloscope. The probes that use an elastomer connector are really cheap and some have posted break-out board designs for these probes on this forum. The TLA7AA4 modules can be hacked to allow full memory bandwidth and maximum state frequency in a very simple way by sending a couple of SCPI commands.

You could use a scope hooked up to the analog outputs to do protocol decoding. I have written some limited protocol decoders (I2C and SPI IIRC) for the TLA700 series in the past as plugins but I have not managed to get these to work well with the most recent version of the TLA700 software.

mtk:
Probably you could look at DSLogic U3Pro16 and DSLogic U3Pro32 https://www.dreamsourcelab.com/product/dslogic-series/ – 16/32 digital channels. USB 3.0 interface, Up to 1GHz sample rate, Up to 2Gbits hardware memo. The current price for 16-channel version on DreamSourceLab shop is 299 USD https://www.dreamsourcelab.com/shop/logic-analyzer/dslogic-u3pro16/. The software – DSView https://github.com/DreamSourceLab/DSView is not bad, based on sigrok – open-source. Has some issues, but there are people that provide technical support. And it will support much more decoding protocols in comparison to old alternatives.

nctnico:
But the problem with the typical USB logic analysers is that they don't have the elaborate triggering posibilities of a real logic analyser. The ones from Tektronix (and I assume HP/Agilent) have trigger systems that are fully programmable where you can use timers, event counters, states, etc. Basically you can program these using a set of conditions that allow to capture extremely elusive bugs / events. At some point deep memory just runs out.

Or put differently: if you have an oscilloscope with digital inputs (=MSO) + decoding, you are probably better off using that because it also allows to see the digital signals in realtime. Having a USB logic analyser doesn't add much value to your toolbox if you have an MSO.

RoGeorge:

--- Quote from: suspension on January 06, 2023, 05:59:57 pm ---I do quite a lot of FPGA work and use internal chip scope from Xilinx to inspect internal signals. The biggest issue with this approach is that any change requires a re-synthesis/implementation of the design which can take 5-15 minutes for complex designs.
--- End quote ---

Most of the debugging should happen in simulation.

Chipscope ILA is a last resort and only rarely used.  Clipping probes at 300-400MHz most probably will ruin the signal integrity and make one chasing ghosts.  Even if possible to clip the probes, it will take more time to physically attach the probes and to operate the external LA, than the 5-15 minutes needed for a new Chipscope setup.  An external LA won't save time, quite contrary.

Can you give a few examples with what kind of signals you want to probe and/or decode?

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod