Design of Digital Circuit Implementations Using Gate Diffusion Input and CMOS

Gate Diffusion Input (GDI) is a technique of low-power combinational circuit design. Complex logic functions like F1, F2, OR, AND, MUX and NOT can be implemented using just two transistors. GDI reduces area, propagation delay and power consumption of digital circuits, and has lower logic complexity than traditional CMOS and existing pass transistor logic techniques. Low power dissipation is achieved by reducing transistor count. Reducing area lowers the interconnect effects. In this paper, first the logic gates (GDI and CMOS) were implemented in Cadence in 90 nm and gate-libraries were created for these. To estimate the complexity and scalability of GDI, ISCAS-85 benchmark circuits were synthesized using these libraries and compared in terms of area, power and delay. GDI circuits prove to be better in terms of area and power than their CMOS counterparts though slightly slower. They may be made faster by buffering logic after every few stages.