EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: slugrustle on August 30, 2023, 10:59:36 pm
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I'd like to use JTAG boundary scan for bringup of new prototype boards at work. These boards typically have one MCU on them, and I would be mostly testing the functionality of hardware controlled by the MCU.
It would be nice to be able to set pin states, read pin states, and maybe toggle a single pin at a particular frequency. That would let me test things like static levels on logic circuits, gate drivers, relay coil drivers, etc. as well as transition effects. Right now, I basically do that manually by wiring the MCU in reset and soldering in my signal generator at I/O pins of interest.
What software is good for this purpose? Does anyone else here use JTAG boundary scan in a similar way?
I've done a little looking around:
- OpenOCD (https://openocd.org/) is open source. It has some basic JTAG commands, low-level JTAG commands, and it can run SVF files. I ordered an Olimex JTAG adapter and plan to play around a bit with OpenOCD.
- Viveris JTAG Boundary Scanner (https://github.com/viveris/jtag-boundary-scanner) is referenced by other open source projects. It has a GUI. However, it does not appear to have any documentation.
- UrJTAG (http://urjtag.org/) is old school and open source. It seems to have a nice interactive commandline and the ability to play SVF files. I might give it a spin.
- TopJTAG (http://www.topjtag.com/) is closed source with $100 license cost, which is not bad compared to others. It has a GUI and looks nice, but the payment link on the website is broken, and none of the support or contact email addresses work.
- XJTAG (https://www.xjtag.com/) was demoed in Dave's video on JTAG boundary scan (https://www.eevblog.com/forum/blog/eevblog-499-what-is-jtag-and-boundary-scan/msg267806/#msg267806). It looks nice. I think the XJAnalyser software and XJLink2 probe might be good for my purposes, but there's no price on the website. I'll bet it's expensive.
- JTAG Live (https://www.jtaglive.com/product-category/design-and-service/) actually lists prices in their store. I wonder if BuzzPlus ($185) or Clip ($785) would be sufficient for what I'm trying to do. Their adapter is $450.
- Corelis is another big player. Their JTAG starter kit (https://www.corelis.com/products/jtag-products/jtag-starter-kit/) looks very nice, but again, no price on the website. I'm guessing this one is also expensive.
- Flynn Systems (https://flynnsystems.com/products-services/products/) makes a program called Circuit Trace that seems like a good fit. No pricing on the website.
- Intellitech (https://www.intellitech.com/jtag/free-jtag-software-ijtag.asp) presently offers their closed-source NEBULA JTAG software for free. It requires a Xilinx USB Platform Cable II (https://www.xilinx.com/products/boards-and-kits/hw-usb-ii-g.html) ($270) and appears to be highly scriptable with additional abilities to toggle pins and play SVF files. Unfortunately, a company email address is required to download the software, so playing with this at home might be out of the question.
Finally, I suppose it is also possible to go hardcore and control an FTDI FT232HL or similar chip in MPSSE JTAG mode from a computer using FTDI's D2XX drivers. I've used those drivers before, and they have a nice API.
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Many of the JTAG programmers are made around a FTDI chip nowadays, so certainly it is possible to control one. I bet there are plenty of such software projects out there, talking about the FOSS ones. If you go that way, use the FT2232H (IIRC that's the dual channel and the fastest one, but please double check against the available dual channel FTDI models, I'm not sure about the last letter, a dual channel FTDI would be preferable so to have both JTAG and a serial port with your devboard at the same time, and with the same USB cable).
This link tells the JTAG state machine, and gives an example of controlling it: https://www.fpga4fun.com/JTAG.html (https://www.fpga4fun.com/JTAG.html) Not for FTDI chips, but I like that link for it keeps it simple and very brief about JTAG.
I've seen a SVF player for an Arduino as a JTAG programmer and saved these links (but didn't test it), it might need voltage level adapters if your hardware is not 5V tolerant:
https://eeandcs.blogspot.com/2015/08/jtagxsvf-library-for-arduino.html (https://eeandcs.blogspot.com/2015/08/jtagxsvf-library-for-arduino.html)
https://github.com/mrjimenez/JTAG (https://github.com/mrjimenez/JTAG)
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In our Company we are using Boundary Scan for EOL testing / functional testing.
We are using solutions from Göpel, the software is called "cascon":
https://www.goepel.com/embedded-jtag-solutions (https://www.goepel.com/embedded-jtag-solutions)
But i'm not sure if this is your prefered price region..