数字设计原理与实践（三）.

数字设计原理与实践（三）.
DO NOT
COPY
3
c h a p t e r




DO NOT
COPY
Digital Circuits


DO NOT





arketing hype notwithstanding, we live in an analog world, not


M a digital one. Voltages, currents, and other physical quantities
in real circuits take on values that are infinitely variable,
depending on properties of the real devices that comprise the


COPY circuits. 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., 3.14159265358979 volts repres