Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

USB-Blaster: Unable to read device chain - JTAG chain broken

I'm using Ubuntu14.04 and quartus14.1. When I run jtagconfig, I get: $ jtagconfig 1) USB-Blaster [3-6] Unable to read device chain - JTAG chain broken The hardware is correct becaus...
SThor8's avatar
SThor8
Icon for Occasional Contributor rankOccasional Contributor
5 years ago

Hi

I have had the same problem on Ubuntu 18.04 but got it working

Try to enter this in a terminal window

killall jtagd
jtagd --user-start

Then my jtagconfig return this

intelFPGA/18.1/quartus/bin/jtagconfig 
1) USB-Blaster [1-5]
  031050DD   10M50DA(.|ES)/10M50DC

Wait 10 seconds before you try to program the FPGA so the restart takes effect.

Beside creating the rule (as i guess you have done) /etc/udev/rules.d/51-usbblaster.rules

I also did 

sudo apt-get install libudev-dev

But I am not sure if that was necessary

Note that you have to redo 

killall jtagd
jtagd --user-start

Every time it loose connection, this is noway a good solution but at least you can now program it

Regards

jobonono's avatar
jobonono
Icon for New Contributor rankNew Contributor
5 years ago

Hi @SThor8

I tried implementing your solution on my Ubuntu 20.04 machine, but I get an

Command 'jtagd' not found

error.

Any suggestions on what to do?

I can get the USB-blaster to work very sporadically, fiddling with plugging the usb cable in/out of the pc and powering the FPGA on/off

  • SThor8's avatar
    SThor8
    Icon for Occasional Contributor rankOccasional Contributor
    5 years ago

    I do nto have the 'jtagd' command either but 'killall jtagd' works

    I do not know why it is so

    • hxj141's avatar
      hxj141
      Icon for New Contributor rankNew Contributor
      5 years ago

      You have to run it from the file locally. First cd into the directory where you have Quartus installed and then to go to {whatever version number it is}/quartus/bin.

      Check if the jtagd file is there with the command ls, and if it is, simply do the command he posted above but with ./jtagd in the front instead of just jtagd. This'll execute the file as if it was a command

    • CUAlex's avatar
      CUAlex
      Icon for New Contributor rankNew Contributor
      5 years ago

      All of the above solutions do not seem to be working. My error message alternates between JTAG chain broken, and Port Permissions Denied.