ENGG1100|Term2|201415 题香港中文大學 The Chinese University of Hong Kong Truth table example for "OR"operation X X, Y are 2 digital input signals XOR Y We can use a"Truth table"to find the output Because there are n=2 inputs: X,Y So there are 2n=4 rows in the truth table Steps Input: Input: Output W -Fill in Y: 0, 1, 0, 1(from top) X(pay by Y(pay by X OR Y= cas Octopus)(ride on a Fill in x:0,0,1,1 bus) Fill in the outputs 0 0 0 Compute output 1 Output=1 only when er input is 1 V15.02.09 Introduction 18ENGG1100 | Term 2 | 2014-15 Truth table example for “OR” operation • X , Y are 2 digital input signals • We can use a “Truth table” to find the output • Because there are n=2 inputs: X,Y • So there are 2n=4 rows in the truth table • Steps: – Fill in Y: 0,1,0,1(from top) – Fill in X: 0,0,1,1 – Fill in the outputs – Compute output: – Output=1 only when either input is 1 V15.02.09 Introduction 18 Input: X(pay by cash) Input: Y (pay by Octopus) Output W= X OR Y= (ride on a bus) 0 0 0 0 1 1 1 0 1 1 1 1 X Y W= X OR Y