ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Three-state devices Multiplexers.

Slides:



Advertisements
Similar presentations
Part 4: combinational devices
Advertisements

ECE 2110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices Encoders.
Encoders Three-state devices Multiplexers
EE 261 – Introduction to Logic Circuits
Digital Logic Design Week 7 Encoders, Decoders, Multiplexers, Demuxes.
Documentation Standards
Multiplexer. A multiplexer (MUX) is a device which selects one of many inputs to a single output. The selection is done by using an input address. Hence,
ECE 3110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices XOR, Parity Circuits, Comparators.
Speical purpose Encoders/Comparators
Code Converters, Multiplexers and Demultiplexers
MSI Logic Circuits Wen-Hung Liao, Ph.D.. Objectives Analyze and use decoders and encoders in various types of circuit applications. Compare the advantages.
CSCE 211: Digital Logic Design Chin-Tser Huang University of South Carolina.
Multiplexers, Decoders, and Programmable Logic Devices
1 EE365 Three-state Outputs Encoders Multiplexers XOR gates.
Combinational Logic Building Blocks
Combinational Logic and Verilog
ECE 301 – Digital Electronics Multiplexers and Demultiplexers (Lecture #12)
Multiplexer MUX. 2 Multiplexer Multiplexer (Selector)  2 n data inputs,  n control inputs,  1 output  Used to connect 2 n points to a single point.
EE365 Adv. Digital Circuit Design Clarkson University Lecture #8 Buffers, Drivers, Encoders, MUXs & XORs.
طراحی مدارهای منطقی نیمسال دوم دانشگاه آزاد اسلامی واحد پرند.
 Combinational circuit that selects binary information from one of many input lines and directs information to a single output line.
Multiplexers DeMultiplexers XOR gates
Adders, subtractors, ALUs
Figure to-1 Multiplexer and Switch Analog
Combinational Logic Chapter 4.
9/15/09 - L15 Decoders, Multiplexers Copyright Joanne DeGroat, ECE, OSU1 Decoders and Multiplexers.
DIGITAL COMPONENTS By Sohaib.
Combinational Logic Design
Encoders Three-state Outputs Multiplexers XOR gates.
Three-state devices Multiplexers
Documentation Standards Circuit specification. –Description of what the system is supposed to do, including a description of all inputs and outputs and.
ECE 3110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices Adders, subtractors, ALUs.
Fall 2004EE 3563 Digital Systems Design EE3563 Multiplexers  A multiplexer is a digital switch  Allows a device to select a single line from many  Some.
9/15/09 - L15 Decoders, Multiplexers Copyright Joanne DeGroat, ECE, OSU1 Decoders and Multiplexer Circuits.
Combinational Design, Part 3: Functional Blocks
Multiplexers XOR gates. Multiplexers A multiplexer is a digital switch - it connects data from one of n sources to its output. An n-input and b-bit multiplexer.
Kuliah Rangkaian Digital Kuliah 6: Blok Pembangun Logika Kombinasional Teknik Komputer Universitas Gunadarma.
Multiplexers and Demultiplexers, and Encoders and Decoders
1 EE121 John Wakerly Lecture #6 Three-state Outputs Encoders Multiplexers XOR gates.
ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Documentation Standards (contd.)
Chapter 33 Basic Logic Gates. 2 Objectives –After completing this chapter, the student should be able to: Identify and explain the function of the basic.
ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Documentation Standards.
ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices X-OR gates and Parity circuits Comparators Adders, subtractors,
INTRODUCTION.  Upon completing this topic, you should be able to: Illustrate a basic elements of digital computer system and their functions, Depicts.
Code Converters, Multiplexers and Demultiplexers
1 CS 151: Introduction to Digital Design Chapter 2-10 High Impedance Outputs.
CEC 220 Digital Circuit Design Timing Diagrams, MUXs, and Buffers Mon, Oct 5 CEC 220 Digital Circuit Design Slide 1 of 20.
CEC 220 Digital Circuit Design Timing Diagrams, MUXs, and Buffers Friday, February 14 CEC 220 Digital Circuit Design Slide 1 of 18.
CEC 220 Digital Circuit Design Timing Diagrams, MUXs, and Buffers
Lecture #18 Page 1 ECE 4110– Sequential Logic Design Lecture #18 Agenda 1.MSI Demultiplexers 2.MSI Tri-State Buffers 3.MSI Comparators Announcements 1.HW.
Documentation Standards (contd.)
Magnitude Comparator A magnitude comparator is a combinational circuit that compares two numbers, A and B, and then determines their relative magnitudes.
Decoders. A decoder is multiple-input, multiple-output logic circuit that converts coded inputs into coded outputs. Input code with fewer bits than the.
Fall 2004EE 3563 Digital Systems Design EE 3563 Encoders  When a device’s output has few bits than the input, it is usually called an “encoder”  It essentially.
ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Documentation Standards.
Multiplexors Decoders  Decoders are used for forming separate signals for different combination of input signals.  The multiplexer circuit is a digital.
ECE 2110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices Multiplexers.
ECE 2110: Introduction to Digital Systems Chapter 6 Review.
ECE 2110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices XOR and parity check Circuits.
ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Adders,subtractors, ALUs.
EKT 124 MUX AND DEMUX.
ECE 2110: Introduction to Digital Systems
Combinational Circuits
Combinational Logic Circuits
ECE 2110: Introduction to Digital Systems Chapter 6 Combinational Logic Design Practices Encoders.
Magnitude Comparator A magnitude comparator is a combinational circuit that compares two numbers, A and B, and then determines their relative magnitudes.
EET107/3 DIGITAL ELECTRONICS 1
Digital System Design Combinational Logic
Arithmetic Circuits.
Presentation transcript:

ECE 3110: Introduction to Digital Systems Chapter 5 Combinational Logic Design Practices Three-state devices Multiplexers

Three State Buffers/Drivers A buffer/inverter with enable input Buffer Buffer Inverter Inverter Actice High Enable Actice Low Enable Active High Enable Actice Low Enable The device behaves like an ordinary buffer/inverter when the enable input is asserted. The ouput is floating ( High Impedance, Hi-Z ) when the enable input is deasserted ( The input is isolated from the output, behaves as if it did not exist) Application: Controlling the access of a single line/bus by multiple devices

Three-state buffers Output = LOW, HIGH, or Hi-Z. Can tie multiple outputs together, if at most one at a time is driven.

8 sources share a three-state party line

Timing considerations

Standard SSI/MSI 3-state buffers SSI: 74x125, 74x126 (independent enable inputs) MSI: 74x541 and varieties such as 74x540, 74x240, 74x241

Octal noninverting 3-state buffer Hysteresis

Driver application

Pairs of 3-state buffers connected in opposite directions between each pair of pins, so data can be transferred in either direction. DIR determines the direction of transfer (A-->B or B-->A) Three-state transceiver

Transceiver application Bidirectional buses

Multiplexers (mux) Select one of n sources of data to transmit on a bus. Eg. Put between Processor’s registers and ALU A 16-bit processor where 3-bit field specifies on of 8 registers. The 3-bit field is connected to the select inputs of an 8-input, 16-bit mux.

MSI: 74x151 8-input 1-bit multiplexer

74x151 truth table

Other multiplexer varieties 2-input, 4-bit- wide 74x157 4-input, 2-bit- wide 74x153

Expanding Multiplexers 32-to-1 mux

Demultiplexers A mux is used to select one of n sources of data to transmit on a bus. A demultiplexer can be used to route the bus data to one of m destinations. Just the inverse of a mux. A binary decoder with an enable input can be used as a demux. Eg. 74x139 can be used as a 2-bit, 4- output demux.

Homework #10 Work Wakerly problems 5.[16, 17, 18, 19(a,c), 20, 35, 45, 46]. Notes: On all timing calculation problems, describe the circuit path used and show each number in the calculation. For problem 5.19, use real 74x parts ONLY and include specific 74x part numbers for all components used on the diagram. Due: Wed. 11/12/2003

Next… X-OR gates and Parity circuits Comparators Reading Wakerly CH