Layout Design Considerations

Layout -the final step of the design process where the electrical description of the circuit is transformed into its physical representation.The layout is then used for realizing the masks required in the chip fabrication.

Digital layout is made by interconnecting simple blocks (place cells and route between them).
Design criteria: to minimize area and signal delay.

Analog layout: contains networks with limited complexity, rarely reuse specific cells, involves optimizing transistor layouts with muchless concern for interconnections. Design criteria: accuracy and noise immunity. Mixed A-D layout: the main issue is the substrate coupling noise. Design criteria: careful circuit design and scrupulous layout.

Floorplanning–organize the layout to minimize device mismatch and coupling effects