The Composition of Scores

Part Ratio
Homework + Quiz 30%
Final exam 70%

How to Produce a Digital Signal

  1. Discrete sample
  2. Quantitized
  3. Encode
  4. Out

Logic Level

The logic value, like “1” and “0”, which we express in digital circuits, is a range of voltage level.

Example:

Name Voltage
HIGH $2.7\mathrm{V} \leq u \leq 3.3\mathrm{V}$
Unacceptable $0.8\mathrm{V} \leq u \lt 2.7\mathrm{V}$
LOW $0 \leq u \lt 0.8\mathrm{V}$

Basic Components

Gate

Perform fixed logic operations

  1. Not Gate (aka Inverter)
    • Invert the input
  2. AND Gate
    • Produces a HIGH output only when all the inputs are HIGH
  3. OR Gate
    • Produces a LOW output only when all the inputs are LOW
  4. XOR Gate
    • Produces a HIGH output only when all the inputs are oppsite

Fixed-function ICs

Perform fixed specific functions

Adder

  1. 1-bit Adder
    • Add 2 binary number
    • Has two output of carry and sum
  2. Full Adder
    • Add A, B and the carry from the previous full adder
    • Has two output of carry and sum

Example: 74LS283