"Based on the seminal Berkeley RISC, the 29k added a number of significant improvements... One design element used in some of the Berkeley RISC-derived designs is the concept of register windows, a technique used to speed up procedure calls significantly."
https://en.wikipedia.org/wiki/AMD_Am29000
"Based on the seminal Berkeley RISC, the 29k added a number of significant improvements... One design element used in some of the Berkeley RISC-derived designs is the concept of register windows, a technique used to speed up procedure calls significantly."