Digital Fundamentals Tenth Edition Floyd Chapter 1 Floyd

Outline • • • 1 -1 Digital and Analog Quantities 1 -2 Digits, Logic

Analog Quantities • Most natural quantities that we see are analog and vary continuously.

Digital Signal (2) can take values from fix levels (of the Y-axis) only! Floyd,

Example Floyd, Digital Fundamentals, 10 th ed

Digital vs. Analog Signal • Pros: – reduce transmission noise – can process, store,

A Complete Digital Systems Analog Input Analog-to. Digital Converter (ADC) Digital Processing System Digital-to.

Analog and Digital Systems Example • Many systems use a mix of analog and

Digital System Hierarchy Digital Systems Sub Systems Modules Basic Units Circuits Floyd, Digital Fundamentals,

Binary Digits and Logic Levels Digital electronics uses circuits that have two states, which

Digital Waveforms • Digital waveforms change between the LOW and HIGH levels. • A

Pulse Actual pulses are not ideal but are described by the rise time, fall

Periodic Pulse Waveforms Periodic pulse waveforms are composed of pulses that repeats in a

Pulse Definitions • Repetitive pulse waveforms are described by – – frequency and period

Timing Diagrams • A timing diagram is used to show the relationship between two

Serial and Parallel Data can be transmitted by either serial transfer or parallel transfer.

Basic Logic Operations True only if all input conditions are true. True only if

Basic System Functions • AND, OR, and NOT elements can be combined to form

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

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

Basic System Functions The counting function Counter 1 2 3 4 Input pulses 5

Integrated Circuits Cutaway view of DIP (Dual-In-line Pins) chip: DIPs are popular for laboratory

Integrated Circuits Laboratory prototyping. The circuit is wired using DIP chips and tested. Testing

Integrated Circuits Pin 1 Dual in-line package Floyd, Digital Fundamentals, 10 th ed Small

Test and Measurement Instruments The front panel controls for a general-purpose oscilloscope can be

Test and Measurement Instruments The logic analyzer can display multiple channels of digital information

Test and Measurement Instruments The Digital Multimeter (DMM) can make three basic electrical measurements.

Programmable Logic Devices (PLDs) • an alternative to fixed function devices. • can be

Selected Key Terms Analog Being continuous or having continuous values. Digital Related to digits

Selected Key Terms Clock A basic timing signal in a digital system; a periodic

Selected Key Terms Fixed-function A category of digital integrated circuits having functions that logic

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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 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 Floyd, Digital Fundamentals, 10 th ed

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

Example 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. Signal to send: 2 V Transmission Error: 0. 3 V How about when transmission error is 0. 7 V? Floyd, Digital Fundamentals, 10 th ed Analog signal Domain: 0 -5 V Signal received: 2. 3 V Final error: 0. 3 V Digital signal Domain: {0, 1, 2, 3, 4, 5} V Signal received: 2 V Final Error: 0 V

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

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. Floyd, Digital Fundamentals, 10 th ed

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

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. VH(max) HIGH VH(min) Invalid VL(max) LOW VL(min) 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. 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. 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 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 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. Floyd, Digital Fundamentals, 10 th ed

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

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

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

Basic System Functions The counting function Counter 1 2 3 4 Input pulses 5 Floyd, Digital Fundamentals, 10 th ed Parallel 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.

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

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

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

Test and Measurement Instruments 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 Floyd, Digital Fundamentals, 10 th ed 0. 01 V

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 Floyd, Digital Fundamentals, 10 th ed

Selected Key Terms Analog Being continuous or having continuous values. Digital Related to digits or discrete quantities; having a set of discrete values. Binary Having two values or states; describes a number system that has a base of two and utilizes 1 and 0 as its digits. Bit A binary digit, which can be a 1 or a 0. Pulse 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. Floyd, Digital Fundamentals, 10 th ed

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

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