LogicCell Education Module Usage Guide Introduction to Logic and Logic Gates Version 1.00 Date November 2016 PC Services email: [email protected] Reading, UK http://www.pcserviceselectronics.co.uk/LogicCell Copyright 2016 by PC Services LogicCell Usage Guide Page 2 of 46 Contents 1 Introduction..........................................................................................................................................................5 1.1Where Does the Name LogicCell come from ?.............................................................................................6 2 What Is Logic ?....................................................................................................................................................7 2.1A Brief History of Computational Logic.......................................................................................................7 3 LogicCell Setup....................................................................................................................................................9 3.1System Requirements.....................................................................................................................................9 3.2Optional Components....................................................................................................................................9 3.3Pinout of LogicCell........................................................................................................................................9 3.3.1Switch Notes..........................................................................................................................................10 3.4Wiring Up LogicCell...................................................................................................................................11 4 Describing Logic Circuits..................................................................................................................................12 4.1Truth Tables.................................................................................................................................................12 4.2Logic Equations...........................................................................................................................................13 4.3Circuit Diagrams..........................................................................................................................................13 5 Simple Gates.......................................................................................................................................................14 5.1Straight Gates...............................................................................................................................................14 5.1.1Buffer (Unity) Gate................................................................................................................................14 5.1.2AND Gate..............................................................................................................................................14 5.1.3AND Gate Example Circuit...................................................................................................................14 5.1.4OR Gate.................................................................................................................................................15 5.1.5OR Gate Example Circuit......................................................................................................................16 5.2Inverted Output Gates..................................................................................................................................17 5.2.1Inverter (NOT) Gate..............................................................................................................................17 5.2.2NAND Gate...........................................................................................................................................17 5.2.3NAND Gate Example Circuit................................................................................................................17 5.2.4NOR Gate..............................................................................................................................................18 5.2.5NOR Gate Example Circuit...................................................................................................................19 5.3Gate Equivalences........................................................................................................................................20 5.4Gate Size......................................................................................................................................................21 5.5Putting it Together Door Example...............................................................................................................21 5.5.1Extra Truth Table Information...............................................................................................................23 6 Complex Gates...................................................................................................................................................24 6.1XOR Gate.....................................................................................................................................................24 6.2XNOR Gate..................................................................................................................................................24 7 De Morgan’s Law and Usage.............................................................................................................................26 7.1Examples......................................................................................................................................................27 7.1.1De Morgan’s of Gate Proof...................................................................................................................27 7.1.2XOR Gate..............................................................................................................................................28 8 Arithmetic Functions..........................................................................................................................................29 8.1Half Adder....................................................................................................................................................29 8.2Full Adder....................................................................................................................................................30 8.3Larger Adders..............................................................................................................................................31 9 Storage Functions...............................................................................................................................................33 9.1RS Latch.......................................................................................................................................................33 9.1.1RS Latch Example.................................................................................................................................33 9.2D Type Latch...............................................................................................................................................34 9.2.1Transparent............................................................................................................................................34 9.2.2Edge.......................................................................................................................................................36 9.3Storage Logic Functions..............................................................................................................................37 9.3.1Understanding Clocks............................................................................................................................37 9.3.2Examples Note and Switch Bounce.......................................................................................................37 9.3.3Shift Register.........................................................................................................................................38 9.3.4Divide By Two......................................................................................................................................39 9.3.5Counter..................................................................................................................................................39 Version 1.00 © Copyright 2016 by PC Services Page 2 of 46 LogicCell Usage Guide Page 3 of 46 10 Advanced LogicCell Information.....................................................................................................................40 10.1Expanding LogicCell Modules..................................................................................................................40 10.2Alternative Power Source..........................................................................................................................40 10.3Specifications.............................................................................................................................................40 10.3.1Environmental......................................................................................................................................40