EE 121                                            Lecture date: October 1, 2002
Digital Design Laboratory                                            Handout #5

			     Lecture #2 Outline

Reading assignments for weeks 2 and 3:
 * Chapter 1.
 * Chapter 2.  2.1 - 2.6, 2.10, 2.11, 2.13, 2.16
 * Chapter 3.  3.1 - 3.4
 * Chapter 4.  TBA

Chapter 1, executive summary:
 * Digital logic can process digital information and analog values that have
   been converted to digital and produce digital and analog outputs.
 * Digital logic can be implemented using electronic circuits, and the number
   of gates in a device has increased exponential during the past 40 years.
 * Increases in circuit density require software for design (CAD = computer
   aided design).
 * Programmable logic is useful for prototyping and reducing time to market.
   Rule of thumb: PLDs have one-tenth the gates of hard logic.

Chapter 2, executive summary:
 * Number representations: almost universally binary or binary coded decimal.
 * Gray codes cycle through binary representations by changing only one bit at
   each step.
 * Bit vectors can represent objects from a set of objects:
    + ASCII characters (8 bits)
    + Unicode symbols (32 bits) (codes for every language on earth)
    + States of a finite state machine (e.g., traffic light)

Chapter 3, executive summary:
 * Logic values are usually represented by voltage ranges.
 * Logic gates can be built using switches.
 * MOS transistors can act as switches.
 * CMOS logic uses pairs of transistors (one p-type, one n-type) arranged in
   pull-down networks and dual pull-up networks.
 * CMOS logic delays are functions of capacitive loading and wire resistance.
 * Useful special inputs and outputs are not modeled as logic:
    + open drain outputs
    + three-state outputs
    + Schmitt-triggered input
    + transmission gates (T-gates).