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                    NPP               Number System, Boolean Algebra and Logic Circuits             235



                                                  A  B C  00  01    11     10


                                                   0    1     x      0     0


                                                   1    1     0      1     x


                        There is only one uncovered ‘1’ . The adja-  A~ Ho$db EH$ 1 ~Mm h¡ Ÿ& BgHo$ nmg Ho$ EH$ S>m|Q>
                    cent don’t care can be used to draw a pair- (do  Ho$`a H§$S>reZ H$mo boH$a EH$ no`a Am¡a ~Zm gH$Vo h¢
                    not make a single)                          (qgJb Z ~ZmE):
                                                  A  B C  00  01    11     10


                                                   0    1     x      0     0


                                                   1    1     0      1     x

                        We have covered all the 1’s. Therefore con-  My±{H$ gmao 1 H$da hmo JE h¢, Bg{bE ~mH$s ~Mo hþE
                    sider the uncovered ‘X’ as zero. The simplified  S>m|Q> Ho$`a H$mo eyÝ` _mZ boVo h¢ Ÿ& Xmo no`am| Ho$ {bE gab
                    expression for two pairs can be written as:

                    F =  B . C +  B . A                         ì`§OH$ Bg àH$ma go {bI gH$Vo h¢:  F =  B . C +  B . A
                        Note: Stop making groups as soon as you     ZmoQ>- O¡go hr gmao 1 H$da hmo OmE d¡go hr g_yh
                    cover all the 1’s. In this problem if you make  ~ZmZm ~§X H$a X|Ÿ& `{X S>m|Q> Ho$`a H$mo boH$a A{YH$ g_yh
                    one more pair, that will produce unnecessary
                    term.                                       ~ZmVo h¢ Vmo do AZmdí`H$ hm|Jo Am¡a Cggo ì`§OH$ Wmo‹S>m ~‹S>m
                                                                hmo OmEJmŸ& `h JcV hmoJmŸ&
                        (b) Y = πM(1, 3, 7) . d (0, 6)              (b) Y = πM(1, 3, 7) . d (0, 6)
                        The  above expression  contains three       Cnamoº$ ì`§OH$ _| VrZ _oŠñQ>_© VWm Xmo S>m|Q> Ho$`a
                    maxterms and two don’t care conditions. The
                    K-map and the groups can be drawn as:       h¢& BgHo$ J«wn Bg àH$ma ~ZmE Om gH$Vo h¢:
                                                 A  B C  00  01     11    10


                                                  0    x      0     0     1


                                                  1    1     1      0      x

                        As the diagram shows one quad overlaps      EH$ ŠdmS> VWm EH$ no`a EH$ Xygao na Amodabon H$a
                    with one pair. The simplified expression can be  aho h¢& Bg àH$ma Xmo g_yhm| go àmßV nXm| H$m `moJ hr gab
                    written as:  Y =  C +  B . A
                                                                ì`§OH$  h¡:  Y =  C + A . B
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