1 将下列十进制数转换为等值的842lBCD 码、542lBCD 码和余3BCD 码
(1)(54)D;(2)(87
15)D;(3)(239
03)D 1
1 解: ( 1) (54)D =(0101,0100)8421=(1000,0100)5421=(1000,0111)余3 ( 2) (87
15)D =(1000,0111
0001,0101)8421 =(1011,1010
0001,1000)5421 =(1011,1010
0100,1000)余3 ( 3) (239
03)D =(0010,0011,1001
0000,0011)8421 =(0010,0011,1100
0000,0011)5421 =(0101,0110,1100
0011,0110)余3 *讨论:BCD 码是一种四位二进制代码,来特定地表示十进制的十个数码
要注意的是,当最高位,或最低位出现0 时, 不允许省略,必须用四位二进制代码表示每一个十进制数码
1 用代数法化简下列各式: (1)CABCBBCAAC (2)BAABCCBA)( 解: 2
解: ( 1CABCBBCAAC =CABCBBCAAC(摩根定律) =CABCBCBACA)()((摩根定律) =CABCBCCBCACABA(分配律) =CBCBA(吸收律) =BCBA(吸收律) =BC (吸收律) =BC (摩根定律) ( 2) =CBACBA)()((分配律) =CBABA])()[((分配律) =C (互补律) 2
2 用卡诺图法化简下列各式: (1)(A,B,C,D)=∑m(3,4,5,6,9,10,12,13,14,15) (2)(A,B,C,D)=∑m(1,4,6,9,13)+∑d(0,3,5,7,11,15) 2