[Grothendieck]

Niklaus Wirth's Oberon system (http://projectoberon.com/) includes a complete CPU (in Verilog), compiler, and OS. I haven't studied it, though.

For a slightly more common architecture (although hopefully we are entering an FPGA-enabled golden age), try Harris & Harris's "Digital design and computer architecture". It covers the MIPS designs (using both SystemVerilog and VHDL simultaneously) in H&P's "Computer organization and design", but in a more compact and systematic way (omitting H&P's broad but shallow coverage of advanced topics).