Functional simulation of the design

In the ‘Sources’ pane, select the module that you want to test. Then click on ‘Create New Source’ in the ‘Processes’ pane. The ‘New Source Wizard’ window will open - select ‘VHDL Test Bench’ and enter the file name (typically add tb_ prefix to the name of the test module).

Then click ‘Next’.

Then confirm the selection of the module which will be tested by clicking ‘Next’.

You can now click ‘Finish’.

In the window on the right hand side of the screen, the automatically generated testbench skeleton with the tested module instance (UUT) has been opened.

Now you need to add the appropriate stimuli and you can start the simulation.

In the ‘Sources’ pane, switch to ‘Behavioral Simulation’.

Then, in the ‘Sources’ pane, select the field with the testbench file name, and in the ‘Processes’ pane, expand the ‘Xilinx ISE Simulator’ and click on ‘Behavioral Check Syntax’ to validate the files.

Then click on the ‘Simulate Behavioral Model’ field to run the simulation.

Here is the result of the simulation:

You can control the simulation using the icons:

Selecting in the ‘Sources’ pane (‘Sim Instances’ tab) the files belonging to the simulated design, and then in the ‘Processes’ pane (the ‘Sim Objects’ tab) the signals used in these files - you can add new signals to the simulation. Remember to re-initialize the simulation with the following icon:

Then the waveforms of the added signals will be displayed.