Using EDA playground for VHDL simulations

• Type in your browser https://www.edaplayground.com/ then have a look at the web page
• It is recommended to log in, in order to save your work
• You can do that using the Log In button (in the top-right corner)
• You can loggin with your Google or Facebook account
• On the new page, select the language and other settings from the left part:
  • From Languages & Libraries select VHDL
  • You will see the change in the name and the content of the two files: testbench.vhd on the left and design.vhd on the right
  • The code starts with a comment (a line which begins with the symbol -- is a comment in VHDL)
  • You can put your code inside the two files: design.vhd and testbench.vhd
  • If you need, you can add more files using the + symbol from the square box.
  • For now, copy from the webpage of the first DL lab the code for design.vhd and the code for testbench.vhd
  • From the menu Tools and simulators -> Select, select Aldec Riviera Pro 2022.04 (it is a commercial simulator)
  • Another tool that you can select for VHDL (if you do not want Aldec Riviera Pro) is GHDL 0.37, but Aldec Riviera works better
  • Tick into the box Open EPWave after runOpen EPWave after run, in order to visualise the results of the simulations
  • For VHDL simulations you have to select the Top entity.
  • Usually this is the entity from the file testbench.vhd
  • For first VHDL lab, the top entity is named test_bench
  • After you copy the code, press the Save button, then press Run
• If everything is ok, you will see some messages during the compilation and execution, then you will see the waveforms obtained for your simulation model.
• If you have error messages, you have to go to the code line pointed by the error message, fix the code, then again save and run untill it works.
• If you make changes into the code, you have to save them and run again.