This is a course project for Computer Organization in Tsinghua University.
We have implemented a classic five stage pipelined CPU on a Spartan-3E based board. The instruction set architecture we used is derived from MIPS16e.
"Copy and Paste" is fine, because we know it's not easy to build a CPU from scratch.
And we did benefit a lot from copying code written by others in this project.
Just make sure you understand what you are doing.