Forum Discussion
Questa doesn't show UUT under Work
This is for Quartus Prime Standard and Questa Sim (both licensed).
Under the test bench, the instantiated UUT should be present. As I'm a novice I puzzled over what I was doing wrong. However, I started a scratch project using a tutorial and got the same results (YouTube, Rania Hussein, Tutorial). Aside from making syntax adjustments to use Verilog instead of System Verilog, I should have the identical results.
Question - why is the UUT (and therefore the variables in it) not present?
thank you.
When you generate a simulation script for an IP or an example design, it does.
12 Replies
- sstrell
Super Contributor
Any screenshots? Code? Hard to figure out what's going on here without seeing anything you've done.
- jeffrs20
New Contributor
Hello. This is the simple tutorial source file. This compiles without issues. Attached is a screenshot of the Questa RTL sim, showing the testbench, but no DUT.
Thank you.module fullAdder (A,B,cin,sum,cout);input A,B,cin;output sum, cout;assign sum = A ^ B ^ cin;assign cout = A & B | cin & (A ^ B);endmodulemodule fullAdder_testbench();reg A,B,cin;wire sum, cout;fullAdder dut (A, B, cin, sum, cout);initial beginA = 0; B = 0; cin = 0; #10;cin = 1; #10;B = 1; cin = 0; #10;cin = 1; #10;A = 1; B = 0; cin = 0; #10;cin = 1; #10;B = 1; cin = 0; #10;cin = 1; #10;$stop;end //initialendmodule
- sstrell
Super Contributor
You say "compiles without issues," but do you mean in Quartus or in Questa? vsim only starts the simulator. You have to first compile your code in the Questa GUI or with the vlog command. You can generate a simulation script in Quartus that does this (Tools menu).
- jeffrs20
New Contributor
Quartus completes the compile. I attached a copy of the entire log but the final line is:
Info (293000): Quartus Prime Full Compilation was successful. 0 errors, 18 warnings
In Questa, here is a fresh RTL Sim called from Quartus. I attached the log file showing the tb was compiled.
- sstrell
Super Contributor
Successful compilation in Quartus doesn't really matter for a simulation though it's still good to know it compiles successfully.
Now that you've compiled in Questa and started the simulation, you have to add waveforms to the Wave view and then actually advance the simulation (run command).
- jeffrs20
New Contributor
Yes, I understand. But I expect the DUT to be listed between fullAdder_testbench and #INITIAL#18. I would select the DUT and the Objects would be listed, ready to be dragged into the Wave window. However, no DUT is present.
Here is a screenshot of the YouTube tutorial. Note that unlike my project, the DUT is present.
- sstrell
Super Contributor
In Questa, you have to add the +acc option so the command is
vsim work.fullAdder_testbench -voptargs=+acc
In the GUI, this is
This is a change from Modelsim where this wasn't necessary.
- jeffrs20
New Contributor
I found this option. It looks slightly different than yours. But when I change to Apply full... The OK box is grayed out. I also looked inside Quartus to see if there is an option to pass this to the simulator but couldn't find anything applicable.
- sstrell
Super Contributor
No, after compiling, do Simulate menu -> Start Simulation and click Simulation Options. You also have to select the top-level design unit on the Design tab there.
- jeffrs20
New Contributor
Ah. That worked! But why doesn't Quartus have an option to pass this option directly to Questa?
- sstrell
Super Contributor
When you generate a simulation script for an IP or an example design, it does.
- jeffrs20
New Contributor
Thank you very much!
Jeff