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WRES1103
Introductory Digital Concepts
REKABENTUK DIGITAL
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Analog & Digital
Analog• Having continuous values
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Analog & Digital
Digital• Having discrete values
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Analog & Digital
Digital Advantage• Can be processed & transmitted more
efficiently and reliably• Advantage of storage (e.g. compression,
enhancement etc)
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Analog & Digital
An analog Electronic System
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Analog & Digital
A System using Digital and analog methods
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Logic Levels
Example:• High for TTL => 2V to
5V• Low for TTL => 0V to
0.8V• 0.8V to 2V
unacceptable/ never used
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Digital Waveforms
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A Digital Waveform Carries Binary Information
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A Digital Waveform Carries Binary Information
Data Transfer
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Encoding & Decoding Function
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Multiplexer & Demultiplexer
Mux• Switches from several inputs line onto single
output line in a specified timeDemux• Vice versa
Purpose• Data can be transferred from several sources
over one line to a distant location and redistributed to several destination
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Multiplexer & Demultiplexer
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Storage Functions
Flip-flopsRegisters• Formed by several flip-flops
Semiconductor memories• ROM (permanent), RAM (temporary)
Magnetic memories• Floppy, internal hard disk
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Storage Functions
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Storage Functions
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Fixed Function Integrated Circuit
All components make up circuits (transistor, diode, resistors and capacitors) are integral part of that single chip.Logic function set by manufacturer and cannot be altered
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IC Packages
Through-hole mounted• Dual in-line package (DIP)
Surface-mount technology (SMT)• Save space• Smaller than DIP (pins close together)• Example
• Small-outline integrated circuit (SOIC)• Plastic lead chip carrier (PLCC)• Leadless ceramic chip carrier (LCCC)• Flat Pack (FP)
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IC Packages
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IC PackagesExample of SMT package configurations
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Pin NumberingDot always next to pin 1Number increase going counterclockwise.
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Programmable Logic Device (PLD)
SPLDCPLDFPGAWill be discussed in WRES1102 (VHDL)
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Introduction to Test InstrumentsOscilloscope – Analog, Digital
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Introduction to Test Instruments
• Amplitude = (3 div)(1V/div) = 3V• Period = (4 div)(10 µs/div) = 40 µs• Frequency = f = 1/T = 1/40µs = 25 kHz
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Introduction to Test Instruments
Logic Analyzer• Oscilloscope format
• Display single or dual waveform• Timing diagram format
• Can display up to 32 waveform• State table format
• Display data in tabular form (e.g. hex, octal, BCD, ASCII)
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Introduction to Test InstrumentsLogic Analyzer
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Introduction to Test Instruments
Logic Probe• Detect high-level voltage, low-level voltage, single
pulses, repetitive pulses and opens on PCB
Logic Pulser• Produce repetitive pulse waveform
Current tracer• = current probe• Sense pulsating current – locating shorts on PCB
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Introduction to Test Instruments
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Introduction to Test Instruments
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Introduction to Test Instruments
DC Power Supply• Converts AC from standard wall outlet into regulated DC
voltage.Function Generator• Provides pulse waveforms, sine wave, triangular wave
Digital multimeter (DMM)• Measure DC and AC voltage• Measure DC and AC current• resistance
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Introduction to Test Instruments