ModelSim is a multi-language environment by Siemens^[1] (previously developed by Mentor Graphics,^[2]) for simulation of hardware description languages such as VHDL, Verilog and SystemC, and includes a built-in C debugger.^[3][2] ModelSim can be used independently, or in conjunction with Intel Quartus Prime, PSIM,^[4] Xilinx ISE or Xilinx Vivado.^[5] Simulation is performed using the graphical user interface (GUI), or automatically using scripts.^[6]

Mentor HDL simulation products are offered in multiple editions, such as ModelSim PE and Questa Sim.

Questa Sim offers high-performance and advanced debugging capabilities, while ModelSim PE is the entry-level simulator for hobbyists and students.^[2] Questa Sim is used in large multi-million gate designs, and is supported on Microsoft Windows and Linux, in 32-bit and 64-bit architectures.^[2]

ModelSim can also be used with MATLAB/Simulink, using Link for ModelSim.^[7][8] Link for ModelSim is a fast bidirectional co-simulation interface between Simulink and ModelSim.^[8][7] For such designs, MATLAB provides a numerical simulation toolset, while ModelSim provides tools to verify the hardware implementation & timing characteristics of the design.^[8]

ModelSim uses a unified kernel for simulation of all supported languages, and the method of debugging embedded C code is the same as VHDL or Verilog.^[2]

ModelSim and Questa Sim products enable simulation, verification and debugging for the following languages:^[2]

• VHDL
• Verilog
• Verilog 2001
• SystemVerilog
• PSL
• SystemC

• Intel Quartus Prime
• Icarus Verilog
• List of HDL simulators
• NCSim
• Verilator
• Xilinx ISE
• Xilinx Vivado

• Official website