There is a great paper describing very simple OoO risc cpu with nice diagrams and a walk through a few execution cycles - https://ece.umd.edu/~blj/RiSC/RiSC-oo.

There is a great paper describing very simple OoO risc cpu with nice diagrams and a walk through a few execution cycles - https://ece.umd.edu/~blj/RiSC/RiSC-oo.1.pdf https://ece.umd.edu/~blj/RiSC/RiSC-oo.1.pdf