Basics of Circuit Design: Logic Gates
This chapter concentrates on the design of combinational logic functions. The knowledge gained in the last chapter on fabrication is important for combinational logic designtechnology-dependent parameters for minimum size, spacing, and parasitic values largely determine how big a gate circuit must be and how fast it can run. We will start by reviewing some important facts about combinational logic functions. The first family of logic gate circuits we will consider are static, fully complementary gates, which are the mainstay of CMOS design. We will analyze the properties of these gates in detail: speed, power consumption, layout design, testability. We will also study some more advanced circuit familiespseudo-nMOS, DCVS, domino, and low-power gatesthat are important in special design situations. We will also study the delays through wires, which can be much longer than the delays through the gates.