Im Still In Love with My strongXstrong - sutherland-hdl.com.pdfVIP

I’m Still In Love With My X! (but, do I want my X to be an optimist, a pessimist, or eliminated?) Stuart Sutherland SystemVerilog Trainer and Consultant Sutherland HDL, Inc. Portland, Oregon stuart@ Abstract—This paper explores the advantages and hazards of simulation models. A number of conference papers have X-optimism and X-pessimism, and of 2-state versus 4-state been written on this topic. The title of this paper is inspired simulation. A number of papers have been written over the by two earlier papers on X propagation, “The Dangers of years on the problems of optimistic versus pessimistic X Living with an X” by Turpin [1] and “Being Assertive with propagation in simulation. Some papers argue that Verilog/ Your X” by Mills [2], presented in 2003 and 2004, SystemVerilog is overly optimistic, while other papers argue respectively. Both the SystemVerilog standard and that SystemVerilog can be overly pessimistic. Which SystemVerilog simulators have added many new features viewpoint is correct? Just a few years ago, some simulator companies were promising that 2-state simulations would since those papers were written. This paper reiterates deliver substantially faster, more efficient simulation