V22.0436 - Prof. Grishman

Lecture 2: Trends; Introduction to Logic Design

Technology Trends

We continue to learn, at a steady pace, how to fabricate smaller and smaller transistors. This allows for

The cost of a chip has remained (very roughly) constant, so price/performance has been rapidly decreasing. How should this extra circuitry and extra performance be used? We shall return to this issue after discussing processor design.

Logic Design: Combinatorial Circuits

(Text: Appendix B.2 and B.3)

Combinational circuits and gates

combinational circuits: no memory -- output is only a function of current inputs

gates are basic combinational circuits: AND gate, OR gate, inverter (complement), etc.

realization of gates from switches:

Representation of combinational circuits

Examples of combinational circuits