1
\$\begingroup\$

I have a simple VHDL file which can be simulated correctly and that synthesizes with Quartus II-11.0 (web edition). I can interact with switches,leds, seven segments and push buttons.

My problem is that among the 9 Altera DE2 boards I have, only 3 of them behave as expected. The FPGA seems the same...

Visually however, there are little differences on the two kind of boards, but I cannot understand why they don't behave the same :

This one works as expected, while this one does not (notice that e.g capacitors are not the same on the top left).

I am using exactly the same bitstream (pof or sof).

What I am missing ? Where can I find the exact info about these differences ?

\$\endgroup\$
10
  • 1
    \$\begingroup\$ What are the differences? \$\endgroup\$
    – Some Hardware Guy
    Commented Jan 18, 2013 at 16:43
  • \$\begingroup\$ the differences are : push buttons do not react on 6/9 of the boards, nor probably the sliders \$\endgroup\$
    – JCLL
    Commented Jan 18, 2013 at 16:48
  • \$\begingroup\$ what are the differences ? That is my question ! Apparently same "DE2" board with same FPGA "cyclone II C35F672C6N"...so how can I guess the differences ? \$\endgroup\$
    – JCLL
    Commented Jan 18, 2013 at 16:51
  • 1
    \$\begingroup\$ Are you sure the FPGA part numbers match exactly? Over the last several years I have helped lots of kids with their DE1 issues, and this kind of issue is almost always them selecting the wrong FPGA in the project wizard. \$\endgroup\$
    – Matt Young
    Commented Jan 18, 2013 at 17:48
  • 1
    \$\begingroup\$ Well, given the environment, perhaps they were quite forceful with the switches/sliders to where they got damaged. Wouldn't be the first time. \$\endgroup\$
    – Gustavo Litovsky
    Commented Jan 19, 2013 at 0:10

1 Answer 1

Reset to default
1
\$\begingroup\$

I posted my question on altera forum : here

The answer is that it is mandatory to put all unused pins to tri-state.

\$\endgroup\$
1
  • \$\begingroup\$ So, did changing that constraint fix the problem? \$\endgroup\$
    – apalopohapa
    Commented Jan 20, 2013 at 11:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.