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[[Image:ISE - Make New TBW.PNG|thumb|right|125px|Dialog box for creating a new test bench waveform.]]
[[Image:ISE - Make New TBW.PNG|thumb|right|125px|Dialog box for creating a new test bench waveform.]]
Go to '''Project > New Source''' and select "Test Bench Waveform." Give the file a name and choose a parent directory, then click next. The next dialog box will ask you which source file to associate with the text bench waveform file. Select the file you wish to text and click next. Verify the details you just selected and click finish. This will bring up the dialog box shown to the right. Chances are you won't need to change (or even worry about) most of that window. However in the bottom right corner you can see "Initial Length of Test Bench". The default value for that tends to be too small for a design of any size; I generally set it to 10,000. You can try to be clever and change it from 10,000 ns to 10<math>\mu</math>s, but it won't work; changing the time unit adjusts other values across the dialog box. So just type in "10000".
Go to '''Project > New Source''' and select "Test Bench Waveform." Give the file a name and choose a parent directory, then click next. The next dialog box will ask you which source file to associate with the text bench waveform file. Select the file you wish to text and click next. Verify the details you just selected and click finish. This will bring up the dialog box shown to the right. Chances are you won't need to change (or even worry about) most of that window. However in the bottom right corner you can see "Initial Length of Test Bench". The default value for that tends to be too small for a design of any size; I generally set it to 10,000. You can try to be clever and change it from 10,000 ns to 10<math>\mu</math>s, but it won't work; changing the time unit adjusts other values across the dialog box. So just type in "10000" (or whatever other number you feel is best).
If you have an existing .tbw file that you want to use, go to the Sources box, change the pull-down menu to "Behavioral Simulation", and double click on the file you want.
If you have an existing .tbw file that you want to use, go to the Sources box, change the pull-down menu to "Behavioral Simulation", and double click on the file you want.
[[Image:ISE - TBW.PNG|thumb|left|125px|Test bench waveform editor.]]
[[Image:ISE - TBW.PNG|thumb|left|125px|Test bench waveform editor.]]
So now you have your test bench waveform open. Your screen will look something along the lines of the one shown to the left. In the main section of the screen you see the waveforms
So now you have your test bench waveform open. Your screen will look something along the lines of the one shown to the left. In the main section of the screen you see the waveforms for the inputs and outputs. You can change which waveforms are shown. To delete a waveform, click on the name and press the delete key. To add a waveform (including internal signals if you want to monitor those), go to the Processes box in the bottom left and double click on the name of the signal you wish to add to the waveform.
A line will appear as a waveform like the ones in the image. A bus will appear as a thick line with a value on the line and a narrow point at a transition. You can set whether the value is to be displayed in hex, binary, or decimal. You can also click the plus sign next to the name to expand the bus into a set of lines.
To set the values, simply click on the waveforms wherever you want the value to be toggled. If you wish to use one of the 7 non-binary logic levels ([[VHDL_tutorial#VHDL_Resolution_Table|shown here]]) or to set a pattern for ISE to fill in for you, right click on the waveform where you wish to start the pattern or non-binary logic level and select "Set Value." Beware of having too many transitions, as it is possible to crash the program that way.
Once you have defined your input waveforms (don't bother trying to set your output waveforms; those get defined by the simulator), you are now ready to simulate. Go to the Processes box and double click "Simulate Behavioral Model" (under "Xilinx ISE Simulator"). ISE will think for a bit then open a new window like the one shown to the right.