1. Floyd, Digital Fundamentals, 10 th ed Digital Fundamentals Tenth Edition Floyd © 2008 Pearson Education Chapter 1

2. Floyd, Digital Fundamentals, 10 th ed Outline 1-1 Digital and Analog Quantities 1-2 Digits, Logic Levels, and Digital Waveforms 1-3 Basic Logic Operations 1-4 Basic System Functions 1-5 Fixed-Function Integrated Circuits 1-6 Test and Measurement Instruments

3. Floyd, Digital Fundamentals, 10 th ed Analog Quantities Most natural quantities that we see are analog and vary continuously. Digital systems: (1) changes occur discretely

4. Floyd, Digital Fundamentals, 10 th ed Digital Signal (2) can take values from fix levels (of the Y-axis) only!

5. Floyd, Digital Fundamentals, 10 th ed Example

6. Floyd, Digital Fundamentals, 10 th ed Digital vs. Analog Signal Pros: –reduce transmission noise –can process, store, and transmit data more efficiently Cons: –can only assign discrete values to each point. Analog signal Domain: 0-5 V Signal received: 2.3V Final error: 0.3V Digital signal Domain: {0,1,2,3,4,5} V Signal received: 2V Final Error: 0V Signal to send: 2V Transmission Error: 0.3V How about when transmission error is 0.7V?

7. Floyd, Digital Fundamentals, 10 th ed A Complete Digital Systems Analog Input Analog Output Analog-to- Digital Converter (ADC) Digital-to- Analog Converter (DAC) Digital Processing System Computer, Calculator, Watch, Measuring instrument etc.

8. Floyd, Digital Fundamentals, 10 th ed Analog and Digital Systems Example Many systems use a mix of analog and digital electronics to take advantage of each technology. A typical CD player accepts digital data from the CD drive and converts it to an analog signal for amplification.

9. Floyd, Digital Fundamentals, 10 th ed Digital System Hierarchy Digital Systems Sub Systems Modules Basic Units Circuits Latches, Flip-flops Logic Gates Transistors, Resistors, Capacitors

10. Floyd, Digital Fundamentals, 10 th ed Outline 1-1 Digital and Analog Quantities 1-2 Digits, Logic Levels, and Digital Waveforms 1-3 Basic Logic Operations 1-4 Basic System Functions 1-5 Fixed-Function Integrated Circuits 1-6 Test and Measurement Instruments

11. Floyd, Digital Fundamentals, 10 th ed Binary Digits and Logic Levels Digital electronics uses circuits that have two states, which are represented by two different voltage levels called HIGH and LOW. The voltages represent numbers in the binary system. In binary, a single number is called a bit (for binary digit). A bit can have the value of either a 0 or a 1, depending on if the voltage is HIGH or LOW. HIGH LOW V H(max) V H(min) V L(max) V L(min) Invalid

12. Floyd, Digital Fundamentals, 10 th ed Digital Waveforms Digital waveforms change between the LOW and HIGH levels. A positive going pulse is one that goes from a normally LOW logic level to a HIGH level and then back again. Digital waveforms are made up of a series of pulses.

13. Floyd, Digital Fundamentals, 10 th ed Pulse Actual pulses are not ideal but are described by the rise time, fall time, amplitude, and other characteristics.

14. Floyd, Digital Fundamentals, 10 th ed Periodic Pulse Waveforms Periodic pulse waveforms are composed of pulses that repeats in a fixed interval called the period. The frequency is the rate it repeats and is measured in hertz. The clock is a basic timing signal that is an example of a periodic wave. What is the period of a repetitive wave if f = 3.2 GHz? 313 ps

15. Floyd, Digital Fundamentals, 10 th ed Pulse Definitions Repetitive pulse waveforms are described by –frequency and period –amplitude (A) –pulse width (t W ) –duty cycle: the ratio of t W to T Amplitude (A) Pulse width (t W ) Period, T

16. Floyd, Digital Fundamentals, 10 th ed Timing Diagrams A timing diagram is used to show the relationship between two or more digital waveforms, A diagram like this can be observed directly on a logic analyzer.

17. Floyd, Digital Fundamentals, 10 th ed Serial and Parallel Data Data can be transmitted by either serial transfer or parallel transfer. serial parallel

18. Floyd, Digital Fundamentals, 10 th ed Outline 1-1 Digital and Analog Quantities 1-2 Digits, Logic Levels, and Digital Waveforms 1-3 Basic Logic Operations 1-4 Basic System Functions 1-5 Fixed-Function Integrated Circuits 1-6 Test and Measurement Instruments

19. Floyd, Digital Fundamentals, 10 th ed Basic Logic Operations True only if all input conditions are true. True only if one or more input conditions are true. Indicates the opposite condition.

20. Floyd, Digital Fundamentals, 10 th ed Basic System Functions AND, OR, and NOT elements can be combined to form various logic functions. A few examples are: The comparison function Basic arithmetic functions

21. Floyd, Digital Fundamentals, 10 th ed Basic System Functions The encoding function The decoding function

22. Floyd, Digital Fundamentals, 10 th ed Basic System Functions The data selection function

23. Floyd, Digital Fundamentals, 10 th ed Basic System Functions The counting function Input pulses 1 CounterParallel output lines Binary code for 1 Binary code for 2 Binary code for 3 Binary code for 4 Binary code for 5 Sequence of binary codes that represent the number of input pulses counted. 2345

24. Floyd, Digital Fundamentals, 10 th ed Outline 1-1 Digital and Analog Quantities 1-2 Digits, Logic Levels, and Digital Waveforms 1-3 Basic Logic Operations 1-4 Basic System Functions 1-5 Fixed-Function Integrated Circuits 1-6 Test and Measurement Instruments

25. Floyd, Digital Fundamentals, 10 th ed Integrated Circuits Cutaway view of DIP (Dual-In-line Pins) chip: DIPs are popular for laboratory experiments with logic.

26. Floyd, Digital Fundamentals, 10 th ed Integrated Circuits Laboratory prototyping. The circuit is wired using DIP chips and tested. Testing can be done by a computer connected to the system. DIP chips

27. Floyd, Digital Fundamentals, 10 th ed Integrated Circuits Pin 1 Dual in-line package Small outline IC (SOIC)

28. Floyd, Digital Fundamentals, 10 th ed Outline 1-1 Digital and Analog Quantities 1-2 Digits, Logic Levels, and Digital Waveforms 1-3 Basic Logic Operations 1-4 Basic System Functions 1-5 Fixed-Function Integrated Circuits 1-6 Test and Measurement Instruments

29. Floyd, Digital Fundamentals, 10 th ed Test and Measurement Instruments The front panel controls for a general-purpose oscilloscope can be divided into four major groups.

30. Floyd, Digital Fundamentals, 10 th ed Test and Measurement Instruments The logic analyzer can display multiple channels of digital information or show data in tabular form.

31. Floyd, Digital Fundamentals, 10 th ed Test and Measurement Instruments 0.01 V The Digital Multimeter (DMM) can make three basic electrical measurements. Voltage Resistance Current DMMs are useful for checking power supply voltages verifying resistors testing continuity

32. Floyd, Digital Fundamentals, 10 th ed Programmable Logic Devices (PLDs) an alternative to fixed function devices. can be programmed for a specific purpose. cost less and use less board space e.g.: programmable logic array with AND and OR gates

33. Floyd, Digital Fundamentals, 10 th ed Selected Key Terms Analog Digital Binary Bit Pulse Being continuous or having continuous values. Related to digits or discrete quantities; having a set of discrete values. Having two values or states; describes a number system that has a base of two and utilizes 1 and 0 as its digits. A binary digit, which can be a 1 or a 0. A sudden change from one level to another, followed after a time, called the pulse width, by a sudden change back to the original level.

34. Floyd, Digital Fundamentals, 10 th ed Selected Key Terms Clock Gate NOT AND OR A basic timing signal in a digital system; a periodic waveform used to synchronize actions. A logic circuit that performs a basic logic operations such as AND or OR. A basic logic function that performs inversion. A basic logic operation in which a true (HIGH) output occurs only when all input conditions are true (HIGH). A basic logic operation in which a true (HIGH) output occurs when when one or more of the input conditions are true (HIGH).

35. Floyd, Digital Fundamentals, 10 th ed Selected Key Terms Fixed-function logic Programmable logic A category of digital integrated circuits having functions that cannot be altered. A category of digital integrated circuits capable of being programmed to perform specified functions.