You are required to write a behavioral description of an ALU. The ALU should take in two 2-bit numbers have the following functionality:
The output of the ALU will consist of one 2-bit result and a carry/borrow bit.
You are also required to write a testbench for this design. You will have to feed values into your design and demonstrate that it is correct.
In order for certain elements to function correctly, (i.e. wait statements and internal signal tracing) you may be required to use Active-VHDL.
1. Run Active VHDL by clicking on the icon on the desktop. If a window pops up regarding evaluation terms, click on "I Agree"
2. Create a new design and store in in C:\temp (don't forget to move it to your account and remove it from the temp directory when you are finished).
3. Select "Add existing resource files" if you have already typed up your vhdl, otherwise select "Create new source files now"
4. Once you have gotten you files loaded and compiled into Active VHDL, select Simulation->Initialize Simulation.
5. Click on the small button next to the save icon to create a new waveform.
6. Select "Waveform->Add Signals" and add all the signals in your testbench.
7. Push the "Run" button and see if the output is what you hoped it would be.