Worst-case static noise margin criteria for logic circuits and their mathematical equivalence

Various criteria have been formulated in the past for analytically calculating the worst-case static noise margins of logic circuits. Some of these criteria are based on infinitely long chains of gates, others on flip-flop circuits. It is shown that the flip-flop approach is equivalent to an infinitely long chain with respect to the worst-case static noise margin. Furthermore, the formal equivalence of four criteria for this worst-case static noise margin is demonstrated. Additionally, a method for computer simulation is discussed.