数字设计原理与实践四.

数字设计原理与实践(四).DO NOT COPY4c h a p t e rDO NOT COPYCombinationalLogic Design PrinciplesDO NOTogic circuits are classified into two types,“combinational”and L“sequential.”A combinational logic circuit is one whose outputsdepend only on its current inputs.The rotary channel selector knobon an old-fashioned television is like a combinational circuit―its COPY“output”selects a channel based only on the current position of the knob(“input”).The outputs of a sequential logic circuit depend not only on the current in