If you want to learn more there's a website [1] for the WRAMP architecture which goes into a fair bit of detail. The manual specifically is what students are (or at least were when I was at Waikato) given as a resource to understand it.

The toolchain and simulator are also available on GitHub [2], though it looks like the author has their own fork from an older version. A few years ago the the project was ported from a custom board to an off-the-shelf FPGA dev board and the simulator was renamed from "rexsim"/"RexSimulator" to "wsim", hence the difference in name.

[1] https://wramp.wand.nz/

[2] https://github.com/wandwramp