Technical data
ModelSim EE/SE Tutorial  6-45
Lesson 6 - Tcl/Tk and ModelSim 
This lesson is divided into several Tcl examples intended to give you a sense of 
Tcl/Tk’s function within ModelSim. The examples include a custom simulation 
interface created with Tcl/Tk. You must be using ModelSim /PLUS or ModelSim 
/VHDL to complete these exercises.
The goals for this lesson are:
Example 1 - Create a "hello world" button widget. (p52) 
Example 2 - Add a procedure that gets called by a button push. (p52) 
Example 3 - Simulate an intersection with traffic lights. (p53) 
Example 4 - Draw a state machine that represents the simulation. (p57) 
More information on Tcl/Tk
Tcl print references
Sources of information about Tcl include Tcl and the Tk Toolkit by John K. 
Ousterhout, published by Addison-Wesley Publishing Company, Inc., and 
Practical Programming in Tcl and Tk by Brent Welch published by Prentice Hall. 
Tcl online references
The following are a few of the many Tcl references available:
• When using ModelSim make this VSIM Main menu selection: Help > Tcl Man 
Pages.
• Tcl man pages are also available at: www.elf.org/tcltk-man-html/contents.htm
• Tcl/Tk general information is available from the Tcl/Tk Consortium: 
www.tclconsortium.org
• The Scriptics Corporation, John Ousterhout’s company (the original Tcl 
developer): www.scriptics.com
.
How Tcl/Tk works with ModelSim 
ModelSim incorporates Tcl as an embedded library package. The Tcl library 
consists of a parser for the Tcl language, routines to implement the Tcl built-in 
commands, and procedures that allow Tcl to be extended with additional 
commands specific to ModelSim. 










