If you're interested in designing a RISC processor in software, Knuth's full book on MMIX is an interesting and complete read. I am not referring to the short v

If you're interested in designing a RISC processor in software, Knuth's full book on MMIX is an interesting and complete read. I am not referring to the short version published as part of Volume 1 the revised TAOCP, but the full exposition in his book from Springer-Verlang. [1] There he explains the CPU, the memory management, the instruction pipeline. And he builds the assembler for the machine. He worked with David Patterson (of MIPS fame) on the architecture. As to the implementation, Knuth once commented that the coding of the instruction pipeline for MMIX was the hardest programming he'd ever done. Cool stuff! [1] http://www.springer.com/gb/book/9783540669388 http://www.springer.com/gb/book/9783540669388