A 3-VALUE COMPUTER DESIGN VERIFICATION SYSTEM

Experimental three-value simulation system, composed of series of computer programs, is designed for use as engineering tool to verify large (5000 block) logic designs prior to actual construction of hardware and also ensures microprogram and logic compatibility in microprogram-controlled machine; besides binary 1 and 0 values, simulator uses X value, which represents unknown condition and is considered to occur during any transition from one binary value to another; use of this third value to represent transition allows simulator to detect combinational hazards, critical races, and feedback oscillations in machine design.