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Computer Circuit Logic GateWith Boolean LogicYinong WangYoungik SongApril 18th 2011
Table of ContentsIntroductionHistory of Logic Gate and Boolean LogicBasic Logic GateInverting Logic GateApplication of Logic GateBoolean Algebra RulesBoolean ExampleActual Products of Logic GatesSummary and ConclusionReferences
IntroductionAll digital equipment is constructed using a few basic circuit.The basic logic element is called a gate.All logic gate has input and output.High - ON – 1   Low - OFF – 0The gate looks at its input and based on their state and its operation.The gate generates the appropriate output reflecting the decision it has made.Boolean logic or Boolean algebra is a logical calculus which has only two value, ‘true’ or ‘false’.
History of Logic Gate and Boolean Logic1847 – George Boole (1815-1864) published, ‘The Mathematical Analysis of Logic’.1898 – Nikola Tesla filed for patents of devices containing logic gate circuits. Vacuum tubes replaced relays for logic operations.1907 – Lee De Forest’s modification of the Fleming valve can be used as AND logic gate.1924 – Walther Bothe invented the first modern electronic AND gate.1937 – Claude E. Shannon introduced the use of Boolean algebra in the analysis and design of switching circuit.
Basic Logic GatesAND GATE     It has two or more input and a single output.Boolean LogicY = AB  or Y = A·BLogic SymbolSeries CircuitTruth TableElectronic Circuit
Basic logic gates OR GATE     It has two or more input and a single output.Boolean LogicY = A + BLogic SymbolParallel CircuitTruth TableElectronic Circuit
Inverting logic gatesNOT GATE   It is the simplest logic gate. It has only one  input and one output. Logic SymbolBoolean LogicA = ĀTruth TableElectronic Circuit
Inverting logic gatesNAND GATEIt is a combination of NOT gate and AND gateYBoolean LogicY = AB  or Y = A·BTruth TableLogic Symbol
Inverting logic gatesNOR GATEIt is a combination of NOT gate and OR gateYBoolean LogicY = A + BYTruth TableLogic Symbol
Application of Logic GateXOR (Exclusive OR) GATEWhen the inputs are opposite, the output is a HIGH.YBoolean LogicY = AB + ABTruth TableYBoolean LogicY = A + BLogic Symbol
Application of Logic GateXNOR (Exclusive NOR) GATEWhen the inputs are opposite, the output is a LOW.YBoolean LogicY = AB + ABTruth TableYBoolean LogicY = A + BLogic Symbol
Application of Logic GateDECODERA decoder is a circuit that looks at its inputs and determines which binary number is represented by this inputTruth Table
Application of Logic GateENCODEREncoders are opposite of decoder. An encoder takes one input and generates a multi-bit output code.Truth Table
Application of Logic GateFlip FlopThe flip-flop is the basic element for a memory circuit. It is comprised of an assembly of logic gates to permit information to be stored.
Boolean Algebra Rules Commutative law                A+B=B+A                A·B=B·AAssociative lawA+(B+C)=(A+B)+CDistributive law             A·(B+C)=(A·B)+(A·C) Double-Inversion Rule          A = A
Boolean Algebra RulesOR Gate RulesA+0=A           A+A=A            A+1=1            A+Ā=1AND Gate RulesA·0=0            A·1= A            A·A=A            A·Ā=0 DeMorgan’s  TheoremsA·B= A+B             A + B = A·B
Boolean Example
Boolean Example
Boolean Example
Actual Products of Logic Gate
Summary and ConclusionAll digital equipment is constructed using a few logic gate.
The basic logic gates are AND, OR, NOT gate.
Combination logic gates are NAND, NOR, XOR, XNOR gate.

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Computer circuit logic

  • 1. Computer Circuit Logic GateWith Boolean LogicYinong WangYoungik SongApril 18th 2011
  • 2. Table of ContentsIntroductionHistory of Logic Gate and Boolean LogicBasic Logic GateInverting Logic GateApplication of Logic GateBoolean Algebra RulesBoolean ExampleActual Products of Logic GatesSummary and ConclusionReferences
  • 3. IntroductionAll digital equipment is constructed using a few basic circuit.The basic logic element is called a gate.All logic gate has input and output.High - ON – 1 Low - OFF – 0The gate looks at its input and based on their state and its operation.The gate generates the appropriate output reflecting the decision it has made.Boolean logic or Boolean algebra is a logical calculus which has only two value, ‘true’ or ‘false’.
  • 4. History of Logic Gate and Boolean Logic1847 – George Boole (1815-1864) published, ‘The Mathematical Analysis of Logic’.1898 – Nikola Tesla filed for patents of devices containing logic gate circuits. Vacuum tubes replaced relays for logic operations.1907 – Lee De Forest’s modification of the Fleming valve can be used as AND logic gate.1924 – Walther Bothe invented the first modern electronic AND gate.1937 – Claude E. Shannon introduced the use of Boolean algebra in the analysis and design of switching circuit.
  • 5. Basic Logic GatesAND GATE It has two or more input and a single output.Boolean LogicY = AB or Y = A·BLogic SymbolSeries CircuitTruth TableElectronic Circuit
  • 6. Basic logic gates OR GATE It has two or more input and a single output.Boolean LogicY = A + BLogic SymbolParallel CircuitTruth TableElectronic Circuit
  • 7. Inverting logic gatesNOT GATE It is the simplest logic gate. It has only one input and one output. Logic SymbolBoolean LogicA = ĀTruth TableElectronic Circuit
  • 8. Inverting logic gatesNAND GATEIt is a combination of NOT gate and AND gateYBoolean LogicY = AB or Y = A·BTruth TableLogic Symbol
  • 9. Inverting logic gatesNOR GATEIt is a combination of NOT gate and OR gateYBoolean LogicY = A + BYTruth TableLogic Symbol
  • 10. Application of Logic GateXOR (Exclusive OR) GATEWhen the inputs are opposite, the output is a HIGH.YBoolean LogicY = AB + ABTruth TableYBoolean LogicY = A + BLogic Symbol
  • 11. Application of Logic GateXNOR (Exclusive NOR) GATEWhen the inputs are opposite, the output is a LOW.YBoolean LogicY = AB + ABTruth TableYBoolean LogicY = A + BLogic Symbol
  • 12. Application of Logic GateDECODERA decoder is a circuit that looks at its inputs and determines which binary number is represented by this inputTruth Table
  • 13. Application of Logic GateENCODEREncoders are opposite of decoder. An encoder takes one input and generates a multi-bit output code.Truth Table
  • 14. Application of Logic GateFlip FlopThe flip-flop is the basic element for a memory circuit. It is comprised of an assembly of logic gates to permit information to be stored.
  • 15. Boolean Algebra Rules Commutative law A+B=B+A A·B=B·AAssociative lawA+(B+C)=(A+B)+CDistributive law A·(B+C)=(A·B)+(A·C) Double-Inversion Rule A = A
  • 16. Boolean Algebra RulesOR Gate RulesA+0=A A+A=A A+1=1 A+Ā=1AND Gate RulesA·0=0 A·1= A A·A=A A·Ā=0 DeMorgan’s TheoremsA·B= A+B A + B = A·B
  • 20. Actual Products of Logic Gate
  • 21. Summary and ConclusionAll digital equipment is constructed using a few logic gate.
  • 22. The basic logic gates are AND, OR, NOT gate.
  • 23. Combination logic gates are NAND, NOR, XOR, XNOR gate.
  • 24. Using logic gate can be made an affordable circuits such as an encoder, a decoder, memory circuits.
  • 25. Boolean algebra can be determined logic gates and simplified them, so this logic is an important tool used in many of digital circuit.ReferencesHistory of logic gate.http://en.wikipedia.org/wiki/Logic_gate#History_and_developmentHistory of Boolean logic and ruleshttp://www.buzzle.com/articles/boolean-origination-history-and-origin-of-boolean-logic.htmlLogic gates introduction and examplesThe website of Mario Ulcar -> Tutorials-> Digitalhttp://faculty.georgebrown.ca/~mulcar/
  • 26. Thank you for watching our presentationAny questions ?