Lesson 5 - Running a batch-mode simulation

The goals for this lesson are:

Run a batch-mode VHDL simulation

Execute a macro (DO) file

View a saved simulation

Batch-mode allows you to execute several commands that are written in a text file. You create a text file with the list of commands you wish to run, and then specify that file when you start ModelSim. This is particularly useful when you need to run a simulation or a set of commands repeatedly.

			Important: Batch-mode simulations must be run from a DOS or UNIX prompt. In Windows, you get a DOS prompt by selecting Start > Programs > Command Prompt. Unless directed otherwise, enter all commands in this lesson at a DOS or UNIX prompt.

Important: Batch-mode simulations must be run from a DOS or UNIX prompt. In Windows, you get a DOS prompt by selecting Start > Programs > Command Prompt. Unless directed otherwise, enter all commands in this lesson at a DOS or UNIX prompt.

To set up for this lesson you'll need to create a new directory and make it the current directory. Copy this file into your new directory:


\<install_dir>\modeltech\examples\counter.vhd

Create a new design library (Remember, enter these commands at a DOS or UNIX prompt):


vlib work

Map the library:


vmap work work

Then compile the source file:


vcom counter.vhd

You will use a macro file that provides stimulus for the counter. For your convenience, a macro file has been provided with ModelSim. You need to copy this macro file from the installation directory to the current directory:


<install_dir>\modeltech\examples\stim.do

Create a batch file using an editor; name it yourfile. With the editor, put the following on separate lines in the file:


add list -decimal *
do stim.do
write list counter.lst

and save to the current directory.

To run the batch-mode simulation, enter the following at the command prompt:


vsim -do yourfile -wlf saved.wlf counter

This is what you just did in Step 7:

invoked the VSIM simulator on a design unit called "counter"

instructed the simulator to save the simulation results in a log file named saved.wlf by using the -wlf switch

used the contents of yourfile to specify that values are to be listed in decimal, to execute a stimulus file called stim.do, and to write the results to a file named counter.lst, the default for a design named counter

Since you saved the simulation results in saved.wlf, you can view the simulation results by starting up VSIM with its -view switch:


vsim -view saved.wlf

Open these windows with the View menu in the Main window, or the equivalent command at the ModelSim prompt:

view signals list wave


			Note: If you open the Process or Variables windows they will be empty. You are looking at a saved simulation, not examining one interactively; the logfile saved in saved.wlf was used to reconstruct the current windows.

Now that you have the windows open, put the signals in them:


 add wave *
 add list *

Use the available windows to experiment with the saved simulation results and quit when you are ready:


 quit -f

For additional information on the batch and command line modes, please refer to the ModelSim User's Manual.