ModelSim PE Student Edition was a free, size-limited version of Mentor Graphics' ModelSim HDL simulator for students running VHDL or Verilog coursework on Windows. This post, first published in 2010, records what the Student Edition offered and how it was installed. As of November 2026, Siemens (which now owns the former Mentor Graphics tools) states that the Student Edition is not currently available for download, so the update below lists the free simulation options that official vendor pages describe today.
More details about free simulators are here: Free HDL Simulators.
Key takeaways
- ModelSim PE Student Edition (2010) supported VHDL or Verilog (not mixed), ran on Windows x86 only, and was limited to 10,000 lines of executable code.
- As of 1 November 2026, the official Siemens page says ModelSim Student Edition is not currently available for download.
- Siemens points students to their university's Siemens EDA academic program, or to the ModelSim/Questa OEM simulators supplied with FPGA vendor tools.
- Open-source simulators (Icarus Verilog, GHDL, Verilator) and FPGA vendor tools that include a simulator are the practical free routes today.
Update, November 2026: is ModelSim Student Edition still available?
This note was added on 1 November 2026. The original 2010 post follows it unchanged in substance.
- Student Edition status. Siemens' ModelSim Student Edition availability page states that the software is temporarily unavailable. It gives the reason as recent changes in US federal regulations that delayed its ability to deliver free software online.
- Siemens' recommended alternatives. The same page suggests asking your university program administrator to contact the Siemens EDA academic team for access to ModelSim and Questa, or using the ModelSim/Questa OEM simulators from its FPGA partners, linking to Intel's FPGA software, Microsemi (now part of Microchip) FPGA design tools, and Lattice.
- Old product link. The original model.com link in this post now redirects to Siemens' Questa One Sim product page, its current commercial simulator.
- Lattice. The Lattice Radiant software page lists QuestaSim Lattice Edition as included in Radiant, and offers a free Radiant license.
- AMD. AMD's Vivado page says Vivado includes verification and simulation tools and offers license tiers that start with free entry-level access.
- Open source. Icarus Verilog (Verilog), GHDL (VHDL) and Verilator (Verilog and SystemVerilog compiled to C++) are free to use, with no line-count limit.
Licence terms, device support and included features for vendor editions change between releases, so check the vendor's current page before you rely on a specific edition.
Free HDL simulator options compared
| Option | Languages | How you get it | Good for |
|---|---|---|---|
| ModelSim PE Student Edition (2010 version) | VHDL or Verilog, not mixed | Was a free download; currently unavailable per Siemens | Historical reference |
| University academic program (Siemens EDA) | Full ModelSim and Questa | Through your institution | Coursework and research with industry tools |
| QuestaSim Lattice Edition | See Lattice documentation | Included in Lattice Radiant | Designs targeting Lattice FPGAs |
| AMD Vivado simulator | See AMD documentation | Included in Vivado | Designs targeting AMD FPGAs |
| Icarus Verilog | Verilog, some SystemVerilog | Open source | Learning Verilog, small testbenches, scripting |
| GHDL | VHDL | Open source | Learning VHDL, VHDL-2008 work |
| Verilator | Verilog, SystemVerilog (synthesizable subset focus) | Open source | Fast cycle-based simulation of large designs, C++ testbenches |
ModelSim PE Student Edition: the original 2010 post
ModelSim PE Student Edition is a free download of the industry leading ModelSim HDL simulator for use by students in their academic coursework.
ModelSim PE Student Edition highlights
- Support for both VHDL and Verilog designs (non-mixed).
- Intelligent, easy-to-use graphical user interface with TCL interface.
- Project manager and source code templates and wizards.
ModelSim PE Student Edition target use and upgrades
- ModelSim PE Student Edition is intended for use by students in pursuit of their academic coursework and basic educational projects.
- For more complex projects and advanced features of ModelSim, universities and colleges have access to ModelSim SE, the highest configuration of ModelSim, plus Questa and other Mentor Graphics products through the Higher Education Program.
- ModelSim PE Student Edition is not to be used for business use or evaluation.
- Please contact sales for a fully functioning evaluation version of ModelSim PE, DE or SE.
ModelSim PE Student Edition performance
- Capacity: 10,000 lines of executable code.
- Performance (up to capacity): 30% of PE.
- Performance (exceeding capacity): 1% of PE (that is, 100 times slower than PE).
ModelSim PE Student Edition support notice
- No customer support is provided for ModelSim Student Edition.
- Interact with other users and join the ModelSim Student Edition Discussion Forum.
- ModelSim PE Student Edition applies to x86/Windows platforms only.
ModelSim PE Student Edition information
Important information
- To download and install ModelSim PE Student Edition, you must complete all three of the following steps.
- You must be connected to the Internet for the entire download, installation and license request processes.
Step 1: Download the latest software
- To begin the process, download the software from the FTP server by completing the ModelSim PE Student Edition license agreement form from the downloads tab.
- Select the FTP link provided on the confirmation page and download the .exe file.
Step 2: Install the software
- After the file downloads completely, double-click on the .exe file to start the installation process.
Step 3: Complete the license request form
- At the end of the installation process, select Finish and a browser window will open with the License Request form. Note: clicking on an existing license request link from your browser bookmarks or from a link posted on the web will not work.
- Complete the form with all fields and select Request Student Edition to submit.
- Once you complete the license request form, your ModelSim PE Student Edition license file will be emailed to you, together with instructions for installing the license file.
Important information about your installation
- License files are valid only for the current installation of the software on the computer on which the software is installed.
- If you need to re-install the software on a computer, you must go through the entire process of download, installation and submission of the license request form.
- If for any reason you need a new license file, you must go through the entire process of download, installation and submission of the license request form.
Upgrade to Mentor Graphics' Higher Education Program
- For applications requiring the highest simulation performance and advanced verification capabilities, students may access Mentor Graphics' most advanced design and verification tools, including ModelSim SE and Questa Advanced Functional Verification, through their college's membership of Mentor Graphics' Higher Education Program.
- View the Higher Education Program details and learn how your institute can apply.
Note added in 2026: Mentor Graphics is now part of Siemens, and its academic offering is run as the Siemens EDA academic program. Ask your university program administrator for current access.
Your first simulation: the same testbench in ModelSim and in free tools
The quickest way to judge any simulator is to run one small design through it. Here is a 4-bit counter and a self-checking testbench in Verilog.
// counter.v
`timescale 1ns/1ps
module counter (input clk, input rst, output reg [3:0] q);
always @(posedge clk)
if (rst) q <= 4'd0;
else q <= q + 4'd1;
endmodule
// tb_counter.v
`timescale 1ns/1ps
module tb_counter;
reg clk = 0, rst = 1;
wire [3:0] q;
counter dut (.clk(clk), .rst(rst), .q(q));
always #5 clk = ~clk; // 10 ns clock period
initial begin
$dumpfile("counter.vcd");
$dumpvars(0, tb_counter);
#12 rst = 0; // release reset after the first edge
#100 $display("q = %0d", q); // ten rising edges later
if (q !== 4'd10) $display("FAIL");
$finish;
end
endmoduleReset is released at 12 ns, and the rising edges at 15, 25, ... 105 ns increment the counter ten times, so the testbench prints q = 10 at 112 ns. Using !== instead of != makes the check fail on X or Z values as well, which catches a missing reset.
| Step | ModelSim or Questa (command line) | Icarus Verilog |
|---|---|---|
| Create a work library | vlib work | Not needed |
| Compile | vlog counter.v tb_counter.v | iverilog -o sim counter.v tb_counter.v |
| Run | vsim -c tb_counter -do "run -all; quit" | vvp sim |
| View waveforms | Run vsim tb_counter in the GUI, then add wave -r /* and run -all | Open counter.vcd in a VCD viewer such as GTKWave |
For VHDL, ModelSim uses vcom instead of vlog; in GHDL the equivalent steps are ghdl -a (analyse), ghdl -e (elaborate) and ghdl -r (run).
Common mistakes when starting with ModelSim and free simulators
- No `timescale. Delays such as
#5are interpreted in the simulator's default unit, and mixing files with and without a timescale gives warnings or confusing timing. - Forgetting
run -allor$finish. The simulation either stops at the default run length or never ends because the clock keeps toggling. - Mixing languages on a single-language licence. The 2010 Student Edition could not simulate a design that mixed VHDL and Verilog; the same limit applies to some free and OEM editions today.
- Relying on simulation only. Code that simulates correctly may not synthesise as intended. The post on common RTL coding mistakes and how to avoid them covers the usual traps.
- Expecting Verilator to behave like ModelSim. Verilator compiles a design to C++ and focuses on synthesizable code, so timing-driven testbench constructs that ModelSim accepts may need rework.
Related reading
- ModelSim tips and tricks for faster day-to-day use.
- Verilog shift register with a testbench, a good second design to simulate.
- If you are simulating for an FPGA, see what an FPGA is on The Semiconductor Hub glossary, and the verification and validation glossary for simulation terms.
Frequently asked questions
Is ModelSim PE Student Edition still free?
As of 1 November 2026, Siemens' official page says ModelSim Student Edition is not currently available for download. Students can ask their university about the Siemens EDA academic program or use the OEM simulators provided with FPGA vendor tools.
What was the limit of ModelSim PE Student Edition?
The 2010 edition was limited to 10,000 lines of executable code, ran at about 30% of ModelSim PE speed within that limit and about 1% beyond it, supported VHDL or Verilog but not mixed designs, and ran on Windows x86 only.
What is a good free alternative to ModelSim?
Icarus Verilog for Verilog, GHDL for VHDL and Verilator for fast simulation of synthesizable Verilog and SystemVerilog are free and open source. If you target a specific FPGA, the simulator included with that vendor's tools (for example QuestaSim Lattice Edition in Lattice Radiant, or the simulator in AMD Vivado) is often the most convenient choice.
What is the difference between ModelSim and Questa?
Both come from the same Siemens (formerly Mentor Graphics) simulator family. ModelSim was the entry and mid-range HDL simulator, while Questa adds advanced verification features such as fuller SystemVerilog and UVM support, assertions, constrained-random stimulus and coverage. Siemens' current flagship simulator is marketed as Questa One Sim.
Can I use a student or free edition for commercial work?
The 2010 Student Edition licence did not allow business use or evaluation. Vendor free editions have their own terms, so read the licence of the edition you install. Open-source simulators carry their own open-source licences.
for the .5% who continue to use FTP, this is going to be a non-trivial issue. Once it became obvious that we were doing this, we wanted to announce as soon as we knew what our path forward would be.
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