数字设计原理与实践三

数字设计原理与实践(三)DO NOTCOPY3c h a p t e r DO NOTCOPYDigital Circuits DO NOTarketing hype notwithstanding,we live in an analog world,not Ma digital one.Voltages,currents,and other physical quantitiesin real circuits take on values that are infinitely variable,depending on properties of the real devices that comprise theCOPYcircuits.Because real values are continuously variable,we could use a physical quantity such as a signal voltage in a circuit to represent a real number(e.g.,3.14159265358979volts repres