tailieunhanh - Ebook Digital Logic Design EEE-241 (Handouts)

In this lesson, some basic concepts regarding information processing and representation are clarified. These include: “Analog” versus “Digital” parameters and systems, digitization of “Analog” signals, digital representation of information, effect of noise on the reliability and choice of digital system representation. | COMSATS Institute of Information Technology (Virtual Campus) Block F, NISTE Building, H-­‐8/1 Islamabad Pakistan Digital Logic Design EEE-­‐241 Handouts Information Processing and Digital Systems Objectives In this lesson, some basic concepts regarding information processing and representation are clarified. These include: 1. “Analog” versus “Digital” parameters and systems. 2. Digitization of “Analog” signals. 3. Digital representation of information. 4. Effect of noise on the reliability and choice of digital system representation. Digital versus Analog • We live in an “Analog” world. • “Analog” means Continuous • We use the word “Analog” to express phenomena or parameters that have smooth gradual change or movement. • For example, earth’s movement around the sun is continuous or “Analog”. • Temperature is an “Analog” parameter. In making a cup of tea, the temperature of the tea kettle increases gradually or smoothly. • In an “Analog” system, parameters have a continuous range of values Æ just like a mathematical function which is “Continuous” ; in other words, the function has no discontinuity points • The word “Digital”, however, means just the opposite. • In Digital Systems, parameters have a limited set of “Discrete” Values that they can assume. • In Other words, digital parameters don’t have a “Continuous” range. • This means that, digital parameters change their values by “Jumping” from one allowed value to another. • As an example, the day of the month is a parameter that may only assume one value out of a set of limited discrete values {1, 2, 3, ., 31}. • Thus, the day of the month is a parameter may not assume a value of for example, but it rather jumps from a value of 2 to a value of 3 then to 4 and so on with no intermediate values!!! To Summarize: • Analog Systems deal with Continuous Range of values. • Digital Systems deal with a .