Page 256 - FUNDAMENTALS OF COMPUTER
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256                         Fundamentals of Computers                           NPP





                               B
                                                               F



                              A


                               C

                       Problem 3.72                                àíZ 3.72

                      Simplify the following Boolean function     {ZåZ ì`§OH$ H$mo do[aE~b _oqnJ {d{Y go hb
                  using variable mapping method:              H$s{OE:
                                              Y =   B . A  C +  C . B . A  +  C . B . A  +  D . C . B . A
                  Solution:           NPP                     hc:

                      The given expression is:                    {X`m J`m ì`§OH$
                                              Y =   B . A  C +  C . B . A  +  C . B . A  +  D . C . B . A
                      The same expression can be written as:      Bgo Bg àH$ma go ^r {bI gH$Vo h¢

                                                  Y =  m +  m +  m +  m 4  .  D
                                                                  5
                                                        6
                                                             7
                      The K-map can be drawn as: (Three vari-     VrZ do[aE~b K-_on {ZåZmZwgma ~Zm`m Om gH$Vm
                  able)                                       h¡…
                                               A  B .C  00  01   11    10


                                               0    0      0     0      0


                                                1   D      1     1      1

                      Here, two pair will cover three ones and    VrZ 1 H$mo Xmo no`am| _| H$ìha H$a {b`m J`m h¡& A~ D
                  but to cover D consider all ‘1’ as (D +  D ) and  H$mo H$da H$aZo hoVw gmao 1 Ho$ ñWmZ na (D +  D ) aIZo na:
                  make a quad:
                                               A  B C  00  01    11    10


                                               0    0      0     0      0


                                                1   D    D + D D + D D + D
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