sbaj000
New ContributorJoined 4 years ago
User Profile
New Contributor
User Widgets
Contributions
ModelSim Memory allocation failure
Hi, I am trying to generate execution cycle counts for mathematical operations on very large integers using ModelSim. However, beyond a certain input size, I get the following error: # ** Fatal: (vsim-4) ****** Memory allocation failure. ***** # Attempting to allocate 27986416 bytes # Please check your system for available memory and swap space. The largest set of wires I use is about 1.2 million bits. The design involves pipelining multiple channels of 2048-bit numbers for cryptographic applications, so very large bit sizes for wires and regs are unavoidable. I understand that signals take more memory than variables, so I have tried to use variables in my test bench when possible, but I am not able to use them when connecting modules because they cannot be converted to nets. I have also tried to simulate my modules with smaller integer sizes and the testbench executes successfully, so I don't believe it's a problem with the code. I am running ModelSim version 20.1.1 on an Intel Windows 10 machine with 32GB of RAM, but I encounter the same errors using version 18.1. Is there any way to allocate more memory to ModelSim? I am using the 32-bit version that does not require a license and have read that it is capped at 2GB. Is it possible that the net sizes I have described are using all 2GB? And if so, is there another version of ModelSim (or any other modelling software) that can handle such large simulations? I am a graduate student and may have access to other versions/applications through my institution. Thank you in advance.2.2KViews0likes2Comments