Basic digital principles

Chapter Basic digital principles

Teach Yourself Electricity and Electronics Third Edition Book
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Summary of Contents

Teach Yourself Electricity and Electronics Third Edition Book

  • 30CHAPTERBasic digital principlesYOU’VE SEEN HOW DIGITAL SIGNALS DIFFER FROM ANALOG SIGNALS. THE MANI-pulation of digital signals is known as digital logic. Digital logic consists of many—sometimes innumerable—pulses racing around. It can be staggering in terms ofquantity, but it is simple at heart: 1 or 0, high or low, yes or no.Suppose a few electronics engineers from, say, 1950 could ride a time machine tothe present day. They would be flabbergasted at the speed and compactness of digitallogic circuitry. Some might be struck with disbelief. Others would say, “I told you so,” or“I knew it would happen.” And then there would inevitably be the one who would quip,“Is this all the further you’ve gotten?”Well, digital-logic circuits are getting smaller, faster, and more sophisticated everyday.Numbering systemsAny number, such as 35912, can be rendered in some other number base or modulus.Then it’s written differently. But it’s always the same quantity.The decimal systemIn the decimal number system, each digit 0 through 9 represents either itself, or else it-self times some power of 10. The value of the digit depends on its position or place inthe number. In the case of the number 35912, the digit 2 is in the units place, and hasa value of simply 2. The digit 1 is in the 10s place; it takes the value of 1 10110.The digit 9 is in the 100s place, having a value of 9 × 102900. The digit 5 is in the1,000s place, and represents 5 1035000. The digit 3 is in the 10,000s place, andhas a value of 3 10430,000. The total value is the sum of all these: 2 109005,00030,00035,912.555Copyright © 2002, 1997, 1993 by The McGraw-Hill Companies. Click here for terms of use.