1 votes 1 votes Here how do we know which variable of select lines is MSB and LSB ? Do we go in MSB->LSB ordering and take A as MSB and B as LSB or do we go by number taking B as MSB (as it is S1) and A as LSB (as it is S0) ? Digital Logic digital-logic + – Rajesh R asked Oct 28, 2017 Rajesh R 2.9k views answer comment Share Follow See all 6 Comments See all 6 6 Comments reply Show 3 previous comments Rajesh R commented Oct 29, 2017 i edited by Rajesh R Oct 29, 2017 reply Follow Share In case of input lines, I1 will always be (S1)'S0 wherever it's position among the input lines is, right ? @Habibkhan Also, we follow this same priority of S1 and S0 in other devices like decoder also right ? 1 votes 1 votes Habibkhan commented Oct 29, 2017 reply Follow Share Yes correct @Rajesh Kumar . But in decoder there is no selection line ; there is input and output lines , the precedence of whom is shown in the diagram itself. Here also the input lines in the multiplexer are mentioned clearly as I0 , I1 etc .. 2 votes 2 votes Anand Maurya commented Nov 9, 2020 reply Follow Share Select line : S0 LSB Sm MSB Input line : I0 LSB In MSB 0 votes 0 votes Please log in or register to add a comment.