8080 Compatible CPU

On line 717 of cpu8080/tags/update/project/cpu8080.v there is:

6'b110000, 6'b110000: begin

The context is:

714                   // the illegal opcodes behave as NOPs
715
716                   6'b001000, 6'b010000, 6'b011000, 6'b100000, 6'b101000,
717                   6'b110000, 6'b110000: begin
718
719                      state <= `cpus_fetchi; // fetch next instruction
720                      pc <= pc+16'h1; // Next instruction byte
721
722                   end

Is the duplicated entry for 6'b110000 intended?

It should be 0x38, or 6'b111000. That value represents an illegal instruction, and is not covered elsewhere.