Best circuit designing program for designing cpu?

[Superposed_Cat]

Hey all, what is the best software (free) that allows you to build virtual circuits and 'run' them? Something that could support large circuits, such as a cpu?

 

[mfb]

A modern CPU is a huge project.

I built a very simple 16-bit CPU for university some years ago, I think we used Quartus - with a university licence, not the free version. I don't know how much the free version can do. You'll certainly want the feature to make new blocks out of individual circuits to combine them on a higher level, otherwise the circuit diagram will become way too messy.

 

[Superposed_Cat]

A modern CPU is a huge project.

Forgot to mention I'm going for 8 bit. Thank you so much.

 

[JhpMeer]

The person in this Thread is making an 8-bit CPU in simulation software:
https://www.physicsforums.com/threa...th-value-when-cpu-requests-the-001-th.801810/
Maybe he has the program you need.

 

[thankz]

try this site
http://fpgacpu.org/
I'd look at vhdl or Verilog on an fpga

 

[snowman_]

Xilinx ISE is alright if you don't mind using 'old' software, I've used that and modelsim for digital logic simulation before. Like thankz said, either VHDL or verilog will work.