Icarus Verilog [9] is an open source event driven simulator, offering an interface and behavior similar to commercial offerings such as Cadence NC, Synopsys VCS and Mentor Graphics ModelSim.

When developing cycle accurate models, it is important to compare behavior with event driven simulation, to understand any differences, and ensure they are not significant.

Icarus Verilog is capable of simulating ORPSoC at 1-2kHz on a standard PC running Linux.