1、单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,计算机的运算方法,第 六 章,1,1.,最少用几位二进制数即可表示任一五位长的十进制正整数?解:五位长的十进制正整数中,最大的数,99999,满足条件:,2,16,(,=65536,),99999 1/2,;(,2,),X,1/8,;(,3,),1/4 X 1/16,解:(,1,)若要,X 1/2,,只要,a,1,=1,,,a,2,a,6,不全为,0,即可(,a,2,or a,3,or a,4,or a,5,or a,6,=1,);(,2,)若要,X,1/8,,,只要,a,1,a,3,不全为,0,即可(,a,1
2、or a,2,or a,3,=1,),,a,4,a,6,可任取,0,或,1,;,(,3,)若要,1/4 X 1/16,,只要,a,1,=0,,,a,2,可任取,0,或,1,;当,a,2,=0,时,若,a,3,=0,,则必须,a,4,=1,,,且,a,5,、,a,6,不全为,0,(,a,5,or a,6,=1,;若,a3=1,,则,a,4,a,6,可任取,0,或,1,;当,a,2,=1,时,,a,3,a,6,可任取,0,或,1,。,3.,设,x,为整数,,x,补,=1,,,x,1,x,2,x,3,x,4,x,5,,若要求,x -16,,试问,x,1,x,5,应取何值?解:若要,x -16,,需
3、x,1,=0,,,x,2,x,5,任意。(注:,负数绝对值大的反而小,。),4.,设机器数字长为,8,位(含,1,位符号位在内),写出对应下列各真值的原码、补码和反码。,-13/64,,,29/128,,,100,,,-87,解:真值与不同机器码对应关系如下:,真 值,十进制 二进制,原 码 反 码 补 码,-13/64 -0.00 1101 1.001 1010 1.110 0101 1.110 0110,29/128 0.001 1101 0.001 1101 0.001 1101 0.001 1101,100 110 0100 0,110 0100 0,110 0100 0,110 0
4、100,-87 -101 0111 1,101 0111 1,010 1000 1,010 1001,5.,已知,x,补,,求,x,原,和,x,。,x1,补,=1.1100,;,x2,补,=1.1001,;,x3,补,=0.1110,;,x4,补,=1.0000,;,x5,补,=1,,,0101,;,x6,补,=1,,,1100,;,x7,补,=0,,,0111,;,x8,补,=1,,,0000,;,解:,x,补,与,x,原,、,x,的对应关系如下:,x,补,x,原,x,(二进制),x,(十进制),1.1100 1.0100 -0.0100 -1/4,1.1001 1.0111 -0.0111
5、 -7/16,0.1110 0.1110 +0.1110 +7/8,1.0000,无,-1.0000 -1,1,,,0101 1,,,1011 -1011 -11,1,,,1100 1,,,0100 -0100 -4,0,,,0111 0,,,0111 +0111 +7,1,,,0000,无,-10000 -16,6.,设机器数字长为,8,位(含,1,位符号位在内),分,整数,和,小数,两种情况讨论真值,x,为何值时,,x,补,=x,原,成立。解:当,x,为,小数,时,若,x,0,,则,x,补,=x,原,成立;若,x 0,,则当,x=-1/2,时,,x,补,=x,原,成立。当,x,为,整数,时
6、若,x,0,,则,x,补,=x,原,成立;若,x 0,时成立。当,xy,补,,是否有,xy,?,解:若,x,补,y,补,,,不一定,有,x,y,。,x,补,y,补,时,x y,的,结论只在,x 0,、,y 0,,及,x,0,、,y,0,、,y,y,,但由于负数补码的符号位为,1,,则,x,补,y,补,。同样,当,x,0,时,有,x,y,补,。,注意:,1,)绝对值小的负数其值反而大,且负数的绝对值越小,其补码值越大。因此,当,x0,、,yy,补,,必有,xy,。,2,)补码的符号位和数值位为一体,不可分开分析。,3,)完整的答案应分,四种,情况分析,但也可通过充分分析一种不成立的情况获得正确
7、答案。,4,)由于补码,0,的符号位为,0,,因此,x,、,y=0,可归纳到,0,的一类情况讨论。,9.,当十六进制数,9B,和,FF,分别表示为,原码,、,补码,、,反码,、,移码,和,无符号数,时,所对应的十进制数各为多少(设机器数采用一位符号位)?解:真值和机器数的对应关系如下:,十六,进制,真值,无符,号数,原码,反码,补码,移码,9BH,二进制,十进制,1001 1011,155,-11 011,-27,-1100100,-100,-1100101,-101,+11011,+27,FFH,二进制,十进制,1111 1111,255,-1111111,-127,-0000000,-0,
8、0000001,-1,+1111111,+127,注意:,1,),9BH,、,FFH,为机器数,本身含符号位。,2,)移码符号位与原、补、反码相反,数值同补码。,10.,在整数定点机中,设机器数采用,一位符号位,,写出,0,的,原码,、,补码,、,反码,和,移码,,得出什么结论?解:,0,的机器数形式如下:,真值,原码,补码,反码,移码,+0,0,,,00,0,0,,,00,0,0,,,00,0,1,,,00,0,-0,1,,,00,0,0,,,00,0,1,,,11,1,1,,,00,0,结论:补、移码,0,的表示唯一,原、反码不唯一。,注意:本题不用分析不同编码间的其他特性。,11.,已
9、知机器数字长为,4,位,(其中,1,位为符号位,),写出整数定点机和小树定点机中,原码,、,补码,和,反码,的全部形式,并注明其对应的十进制真值。,解:机器数与对应的真值形式如下:,真值,(二进制),真值,(十进制),原码,反码,补码,整,数,+111,+110,+101,+100,+011,+010,+001,+000,+7,+6,+5,+4,+3,+2,+1,+0,0,,,111,0,,,110,0,,,101,0,,,100,0,,,011,0,,,010,0,,,001,0,,,000,同,原,码,同,原,码,续表,1,:,真值,(二进制),真值,(十进制),原码,反码,补码,整,数,
10、1000,-111,-110,-101,-100,-011,-010,-001,-000,-8,-7,-6,-5,-4,-3,-2,-1,-0,无,1,,,111,1,,,110,1,,,101,1,,,100,1,,,011,1,,,010,1,,,001,1,,,000,无,1,,,000,1,,,001,1,,,010,1,,,011,1,,,100,1,,,101,1,,,110,1,,,111,1,,,000,1,,,001,1,,,010,1,,,011,1,,,100,1,,,101,1,,,110,1,,,111,0,,,000,续表,2,:,真值,(二进制),真值,(十进制
11、原码,反码,补码,小,数,+0.111,+0.110,+0.101,+0.100,+0.011,+0.010,+0.001,+0.000,+7/8,+3/4,+5/8,+1/2,+3/8,+1/4,+1/8,+0,0.111,0.110,0.101,0.100,0.011,0.010,0.001,0.000,同,原,码,同,原,码,续表,3,:,真值,(二进制),真值,(十进制),原码,反码,补码,小,数,-1.000,-0.111,-0.110,-0.101,-0.100,-0.011,-0.010,-0.001,-0.000,-1,-7/8,-3/4,-5/8,-1/2,-3/8,-1
12、/4,-1/8,-0,无,1.111,1.110,1.101,1.100,1.011,1.010,1.001,1.000,无,1.000,1.001,1.010,1.011,1.100,1.101,1.110,1.111,1.000,1.001,1.010,1.011,1.100,1.101,1.110,1.111,0.000,12.,设浮点数格式为:,阶码,5,位(,含,1,位阶符),尾数,11,位(含,1,位数符)。,写出,51/128,、,27/1024,、,7.375,、,-86.5,所对应的机器数。要求如下:(,1,)阶码和尾数均为原码;(,2,)阶码和尾数均为补码;(,3,)阶码为
13、移码,尾数为补码。,(注:题意中应补充规格化数的要求。),解:据题意画出该浮点数的格式:,1 4 1 10,阶符 阶码 数符 尾数,注意:,1,)正数补码,不,“,变反,+1,”,。,2,)机器数末位的,0,不能省,。,将十进制数转换为二进制:,x,1,=51/128=,(,0.011 001 1,),2,=2,-1,(,0.110 011,),2,x,2,=-27/1024=,(,-0.000 001 101 1,),2,=2,-5,(,-0.110 11,),2,x,3,=7.375=,(,111.011,),2,=2,3,(,0.111 011,),2,x,4,=-86.5=,(,-1
14、010 110.1,),2,=2,7,(,-0.101 011 01,),2,则以上各数的浮点规格化数为:,(,1,),x,1,浮,=1,,,0001,;,0.110 011 000 0,(,2,),x,1,浮,=1,,,1111,;,0.110 011 000 0,(,3,),x,1,浮,=0,,,1111,;,0.110 011 000 0,(,1,),x,2,浮,=1,,,0101,;,1.110 110 000 0,(,2,),x,2,浮,=1,,,1011,;,1.001 010 000 0,(,3,),x,2,浮,=0,,,1011,;,1.001 010 000 0,(,1,),
15、x,3,浮,=0,,,0011,;,0.111 011 000 0,(,2,),x,3,浮,=0,,,0011,;,0.111 011 000 0,(,3,),x,3,浮,=1,,,0011,;,0.111 011 000 0,(,1,),x,4,浮,=0,,,0111,;,1.101 011 010 0,(,2,),x,4,浮,=0,,,0111,;,1.010 100 110 0,(,3,),x,4,浮,=1,,,0111,;,1.010 100 110 0,注:以上浮点数也可采用如下格式:,1 1 4 10,数符 阶符 阶码 尾数,此时只要将上述答案中的数符位移到最前面即可。,13.,浮
16、点数格式同上题,当阶码基值分别取,2,和,16,时,(,1,)说明,2,和,16,在浮点数中如何表示。(,2,),基值不同,对浮点数什么有影响?(,3,)当阶码和尾数均用补码表示,且尾数采用规格化形式,给出两种情况下所能表示的,最大正数,和,非零最小正数,真值。解:(,1,)阶码基值不论取何值,在浮点数中均为,隐含,表示,即:,2,和,16,不出现在浮点格式中,仅为人为的,约定,。,(,2,)当基值不同时,对数的表示范围和精度都有影响。即:在浮点格式不变的情况下,,基越大,可表示的浮点数范围越大,但精度越下降。,(,3,),r=2,时,,最大正数,的浮点格式为:,0,,,1111,;,0.11
17、1 111 111 1,其真值为:,N,+max,=2,15,(,1-2,-10,),非零最小规格化正数,浮点格式为:,1,,,0000,;,0.100 000 000 0,其真值为:,N,+min,=2,-16,2,-1,=2,-17,r=16,时,,最大正数,的浮点格式为:,0,,,1111,;,0.1111 1111 11,其真值为:,N,+max,=16,15,(,1-2,-10,),非零最小规格化正数,浮点格式为:,1,,,0000,;,0.0001 0000 00,其真值为:,N,+min,=16,-16,16,-1,=16,-17,14.,设浮点数字长为,32,位,,欲表示,6,
18、万,间的十进制数,在保证数的最大精度条件下,除阶符、数符各取一位外,阶码和尾数各取几位?按这样分配,该浮点数溢出的条件是什么?解:若要保证数的最大精度,应取,阶的基,=2,。若要表示,6,万间的十进制数,由于,32768,(,2,15,),6,万,或,)。,2,)应用,十进制,2,的幂,形式分阶、尾两部分表示,这样可反映出浮点数的格式特点。括号不要乘开,不要用十进制小数表示,不直观、不精确且无意义。,3,),原码正、负域,对称,,补码正、负域,不对称,,浮点数阶、尾也如此。特别要注意浮点负数补码规格化范围。(满足条件:,数符,MSB,位,=1,),17.,设机器数字长为,8,位,(含,1,位符
19、号位),对下列各机器数进行算术,左移一位、两位,,,算术右移一位,、,两位,,讨论结果是否正确。,x,1,原,=0.001 1010,;,x,2,原,=1.110 1000,;,x,3,原,=1.001 1001,;,y,1,补,=0.101 0100,;,y,2,补,=1.110 1000,;,y,3,补,=1.001 1001,;,z,1,反,=1.010 1111,;,z,2,反,=1.110 1000,;,z,3,反,=1.001 1001,。,解:,算术左移一位,:,x,1,原,=0.011 0100,;正确,x,2,原,=1.101 0000,;溢出(丢,1,)出错,x,3,原,=
20、1.011 0010,;正确,y,1,补,=0.010 1000,;溢出(丢,1,)出错,y,2,补,=1.101 0000,;正确,y,3,补,=1.011 0010,;溢出(丢,0,)出错,z,1,反,=1.101 1111,;溢出(丢,0,)出错,z,2,反,=1.101 0001,;正确,z,3,反,=1.011 0011,;溢出(丢,0,)出错,算术左移两位,:,x,1,原,=0.110 1000,;正确,x,2,原,=1.010 0000,;溢出(丢,11,)出错,x,3,原,=1.110 0100,;正确,算术左移两位:,y,1,补,=0.101 0000,;溢出(丢,10,)出
21、错,y,2,补,=1.010 0000,;正确,y,3,补,=1.110 0100,;溢出(丢,00,)出错,z,1,反,=1.011 1111,;溢出(丢,01,)出错,z,2,反,=1.010 0011,;正确,z,3,反,=1.110 0111,;溢出(丢,00,)出错,算术右移一位:,x,1,原,=0.000 1101,;正确,x,2,原,=1.011 0100,;正确,x,3,原,=1.000 1100(1),;丢,1,,产生误差,y,1,补,=0.010 1010,;正确,y,2,补,=1.111 0100,;正确,y,3,补,=1.100 1100(1),;丢,1,,产生误差,算
22、术右移一位:,z,1,反,=1.101 0111,;正确,z,2,反,=1.111 0100(0),;丢,0,,产生误差,z,3,反,=1.100 1100,;正确,算术右移两位:,x,1,原,=0.000 0110,(,10,);产生误差,x,2,原,=1.001 1010,;正确,x,3,原,=1.000 0110,(,01,);产生误差,y,1,补,=0.001 0101,;正确,y,2,补,=1.111 1010,;正确,y,3,补,=1.110 0110,(,01,);产生误差,z,1,反,=1.110 1011,;正确,z,2,反,=1.111 1010,(,00,);产生误差,z
23、3,反,=1.110 0110,(,01,);产生误差,18.,试,比较,逻辑移位和算术移位。解:逻辑移位和算术移位的,区别,:,逻辑移位,是对逻辑数或无符号数进行的移位,其特点是不论左移还是右移,,空出位均补,0,,移位时不考虑符号位。,算术移位,是对带符号数进行的移位操作,其关键规则是移位时,符号位保持不变,,空出位的补入值与数的正负、移位方向、采用的码制等有关。补码或反码右移时具有,符号延伸特性,。左移时可能,产生溢出,错误,右移时可能,丢失精度,。,19.,设机器数字长为,8,位(含,1,位符号位),用补码运算规则计算下列各题。(,1,),A=9/64,,,B=-13/32,,求,A
24、B,;,(,2,),A=19/32,,,B=-17/128,,求,A-B,;,(,3,),A=-3/16,,,B=9/32,,求,A+B,;,(,4,),A=-87,,,B=53,,求,A-B,;,(,5,),A=115,,,B=-24,,求,A+B,。解:(,1,),A=9/64=,(,0.001 0010,),2,B=-13/32=,(,-0.011 0100,),2,A,补,=0.001 0010 B,补,=1.100 1100,A+B,补,=0.0 0 1 0 0 1 0 +1.1 0 0 1 1 0 0 1.1 0 1 1 1 1 0,无溢出,A+B=,(,-0.010 0010,
25、2,=-17/64,(,2,),A=19/32=,(,0.100 1100,),2,B=-17/128=,(,-0.001 0001,),2,A,补,=0.100 1100 B,补,=1.110 1111 -B,补,=0.001 0001,A-B,补,=0.1 0 0 1 1 0 0 +0.0 0 1 0 0 0 1 0.1 0 1 1 1 0 1,无溢出,A-B=,(,0.101 1101,),2,=93/128,(,3,),A=-3/16=,(,-0.001 1000,),2,B=9/32=,(,0.010 0100,),2,A,补,=1.110 1000 B,补,=0.010 010
26、0,A+B,补,=1.1 1 0 1 0 0 0 +0.0 1 0 0 1 0 0 0.0 0 0 1 1 0 0,无溢出,A+B=,(,0.000 1100,),2,=3/32,(,4,),A=-87=,(,-101 0111,),2,B=53=,(,110 101,),2,A,补,=1,,,010 1001 B,补,=0,,,011 0101 -B,补,=1,,,100 1011,A-B,补,=1,,,0 1 0 1 0 0 1 +1,,,1 0 0 1 0 1 1 0,,,1 1 1 0 1 0 0,溢出,A-B=,(,-1,,,000 1100,),2,=-140,(,5,),A=11
27、5=,(,111 0011,),2,B=-24=,(,-11 000,),2,A,补,=0,,,111 0011 B,补,=1,,,110 1000,A+B,补,=0,,,1 1 1 0 0 1 1 +1,,,1 1 0 1 0 0 0 0,,,1 0 1 1 0 1 1,无溢出,A+B=,(,101 1011,),2,=91,注意:,1,、单符号位运算要用单符号位的判断方法判溢出;,2,、结果的真值形式上要和原始数据一致。,20.,用原码一位乘、两位乘和补码一位乘(,Booth,算法)、两位乘计算,xy,。(,1,),x=0.110 111,,,y=-0.101 110,;,(,2,),x=
28、0.010 111,,,y=-0.010 101,;,(,3,),x=19,,,y=35,;,(,4,),x=0.110 11,,,y=-0.111 01,。,解:先将数据转换成所需的机器数,然后计算,最后结果转换成真值。(,1,),x,原,=x=0.110111,,,y,原,=1.101110 x*=0.110111,,,y*=0.101110 x,0,=0,,,y,0,=1,,,z,0,=x,0,y,0,=0,1=1,x*,y*=0.100 111 100 010,xy,原,=1.,100 111 100 010,x,y=-0.,100 111 100 010,原码一位乘:,部分积 乘数
29、y*0.0 0 0 0 0 0 .1 0 1 1 1,0,+0,1,0.0 0 0 0 0 0 0.1 0 1 1,1,+x*,+0.1 1 0 1 1 1 0.1 1 0 1 1 1,1 0.0 1 1 0 1 1 1 0.1 0 1,1,+x*,+0.1 1 0 1 1 1 1.0 1 0 0 1 0,1 0.1 0 1 0 0 1 0 1 0 .1 0,1,+x*,+0.1 1 0 1 1 1 1.1 0 0 0 0 0,1 0.1 1 0 0 0 0 0 0 1 0.1,0,+0,1 0.0 1 1 0 0 0 0 0 0 1 0.,1,x*,+0.1 1 0 1 1 1 1.0 0
30、 1 1 1 1,1 0.1 0 0 1 1 1 1 0 0 0 1 0,2x*=01.101110,,,-x*,补,=-x,补,=1.001001,原码两位乘:,部分积 乘数,Cj 0 0 0.0 0 0 0 0 0 0 0.1 0 1 1,1 0,0 +0 0 1.1 0 1 1 1 0 +2x*0 0 1.1 0 1 1 1 0 0,2 0 0 0.0 1 1 0 1 1 1 0 0 0.1 0,1 1,+1 1 1.0 0 1 0 0 1 +-x*,补,1 1 1.1 0 0 1 0 0 1,2,1 1 1.1 1 1 0 0 1 0 0 1 0 0 0.,1 0,+,1 1 1.0
31、0 1 0 0 1 +-x*,补,1 1 1.0 0 0 0 1 0,1,2,1 1 1.1 1 0 0 0 0 1 0 0 0 1 0,0 0,.,+0 0 0.1 1 0 1 1 1 +x*0 0 0.1 0 0 1 1 1 1 0 0 0 1 0 0,结果同一位乘,,x,y=-0.,100 111 100 010,x,补,=x=0.110111y,补,=1.010010-x,补,=1.0010012x,补,=01.101110-2x,补,=10.010010,x,y,补,=1.011 000 011 110 0,xy=-0.100 111 100 010 0,补码一位乘、两位乘运算过程如
32、下:,补码一位乘:,部分积 乘数,y,补,y,n+1,0 0.0 0 0 0 0 0 1.0 1 0 0 1,0 0,+0,1 0,0.0 0 0 0 0 0 0 1.0 1 0 0,1 0,+1 1.0 0 1 0 0 1 +-x,补,1 1.0 0 1 0 0 1,1 1 1.1 0 0 1 0 0 1 0 1.0 1 0,0 1,+0 0.1 1 0 1 1 1 +x,补,0 0.0 1 1 0 1 1,1 0 0.0 0 1 1 0 1 1 1 0 1 .0 1,0 0,+0,1 0 0.0 0 0 1 1 0 1 1 1 0 1.0,1 0,+1 1.0 0 1 0 0 1,+-x,
33、补,1 1.0 0 1 1 1 1,1 1 1.1 0 0 1 1 1 1 1 1 1 0 1.,0 1,+0 0.1 1 0 1 1 1 +x,补,0 0.0 1 1 1 1 0,1 0 0.0 0 1 1 1 1 0 1 1 1 1 0,1 .0,+,1 1.0 0 1 0 0 1 +-x,补,1 1.0 1 1 0 0 0 0 1 1 1 1 0,0,清,0,补码两位乘:,部分积 乘数,y,n+1,0 0 0.0 0 0 0 0 0 1 1.0 1 0 0,1 0 0,+1 1 0.0 1 0 0 1 0 +-2x,补,1 1 0.0 1 0 0 1 0,2 1 1 1.1 0 0 1
34、0 0 1 0 1 1.0 1,0 0 1,+0 0 0.1 1 0 1 1 1 +x,补,0 0 0.0 1 1 0 1 1,2,0 0 0.0 0 0 1 1 0 1 1 1 0 1 1.,0 1 0,+,0 0 0.1 1 0 1 1 1 +x,补,0 0 0.1 1 1 1 0 1,2,0 0 0.0 0 1 1 1 1 0 1 1 1 1 0,1 1 .0,+1 1 1.0 0 1 0 0 1 +-x,补,1 1 1.0 1 1 0 0 0 0 1 1 1 1 0,0 0,.,清,0,结果同补码一位乘,,x,y=-0.,100 111 100 010 00,(,2,),x=-0.01
35、0111,,,y=-0.010101 x,原,=1.010111,,,y,原,=1.010101 x*=0.010111,,,y*=0.010101,-x*,补,=1.101001,,,2x*=0.101110 -2x*,补,=1.010010,x,0,=1,,,y,0,=1,,,z,0,=x,0,y,0,=1,1=0 x,补,=1.101001,,,y,补,=1.101011 -x,补,=0.010111,,,2x,补,=1.010010 -2x,补,=0.101110,x*,y*=0.000 111 100 011,xy,原,=0.,000 111 100 011 xy,补,=0.,000
36、 111 100 011 0,x,y=0.,000 111 100 011,运算过程如下:,原码一位乘:,部分积 乘数,y*0.0 0 0 0 0 0 .0 1 0 1 0,1,+x*,+,0.0 1 0 1 1 1 0.0 1 0 1 1 1,1 0.0 0 1 0 1 1 1,.0 1 0 1,0,+0,1 0.0 0 0 1 0 1 1 1,.0 1 0,1,+x*,+0.0 1 0 1 1 1 0.0 1 1 1 0 0,1 0.0 0 1 1 1 0 0 1 1 .0 1,0,+0,1 0.0 0 0 1 1 1 0 0 1 1.0,1,+x*,+0.,0 1 0 1 1 1,0.0
37、 1 1 1 1 0,1 0.0 0 1 1 1 1 0 0 0 1 1.0 +0,1 0.0 0 0 1 1 1 1 0 0 0 1 1,原码两位乘:,部分积 乘数,y*Cj 0 0 0.0 0 0 0 0 0 0 0.0 1 0 1,0 1,0 +0 0 0.0 1 0 1 1 1 +x*0 0 0.0 1 0 1 1 1 0,2 0 0 0.0 0 0 1 0 1 1 1 0 0.0 1,0 1,+,0 0 0.0 1 0 1 1 1,+x*0 0 0.0 1 1 1 0 0 0,2 0 0 0.0 0 0 1 1 1 0,0 1 1 0 0.,0 1,+0 0 0.0 1 0 1 1
38、1,+x*0 0 0.0 1 1 1 1 0,0,2 0 0 0.0 0 0 1 1 1 1 0 0,0 1 1,0 0,.,+0,结果同一位乘,,x,y=0.,000 111 100 011,补码一位乘:,部分积 乘数,y,补,y,n+1,0 0.0 0 0 0 0 0 1.1 0 1 0 1,1 0,+0 0.0 1 0 1 1 1 +-x,补,0 0.0 1 0 1 1 1,1,0 0.0 0 1 0 1 1 1 1.1 0 1 0,1 1,+0,1,0 0.0 0 0 1 0 1 1 1 1.1 0 1,0 1,+1 1.1 0 1 0 0 1 +x,补,1 1.1 0 1 1 1 0
39、1 1 1.1 1 0 1 1 1 0,1 1 1 .1 0,1 0,+,0 0.0 1 0 1 1 1 +-x,补,0 0.0 0 1 1 1 0,1 0 0.0 0 0 1 1 1 0 0,1 1 1.1,0 1,+1 1.1 0 1 0 0 1 +x,补,1 1.1 1 0 0 0 0,1 1 1.1 1 1 0 0 0 0 0 0,1 1 1.,1 0,+,0 0.0 1 0 1 1 1 +-x,补,0 0.0 0 1 1 1 1,1,0 0.0 0 0 1 1 1 1,0 0 0,1 1,1 .1,+0,补码两位乘:,部分积 乘数,y,n+1,0 0 0.0 0 0 0 0 0 1
40、 1.1 0 1 0,1 1 0,+0 0 0.0 1 0 1 1 1 +-x,补,0 0 0.0 1 0 1 1 1,2,0 0 0.0 0 0 1 0 1 1 1 1 1.1 0,1 0 1,+0 0 0.0 1 0 1 1 1 +-x,补,0 0 0.0 1 1 1 0 0,2 0 0 0.0 0 0 1 1 1 0 0,1 1 1 1.,1 0 1,+,0 0 0.0 1 0 1 1 1 +-x,补,0 0 0.0 1 1 1 1 0,2 0 0 0.0 0 0 1 1 1 1 0 0 0,1 1,1 1,.,1,清,0,+0,结果同补码一位乘,,x,y=0.,000 111 100
41、011 00,(,3,),x=19,,,y=35 x=,(,10 011,),2,,,y=,(,100 011,),2,x*=x,原,=,x,补,=,0,,,010 011 y*=y,原,=,y,补,=,0,,,100 011,-x*,补,=-x,补,=1,,,101 101 2x*=2x,补,=0,,,100 110 -2x*,补,=-2x,补,=1,,,011 010,x,0,=0,,,y,0,=0,,,z,0,=x,0,y,0,=0,0=0,x,y=x*,y*=xy,原,=,xy,补,=,0,,,001 010 011 001 =,(,665,),10,运算过程如下:,原码一位乘:,部分
42、积 乘数,y*0,,,0 0 0 0 0 0 1 0 0 0 1,1,+x*,+,0,,,0 1 0 0 1 1 0,,,0 1 0 0 1 1,1,0,,,0 0 1 0 0 1 1,1,0 0 0,1,+x*,+,0,,,0 1 0 0 1 1 0,,,0 1 1 1 0 0,1,0,,,0 0 1 1 1 0 0 1,1,0 0,0,+0,1,0,,,0 0 0 1 1 1 0 0 1,1,0,0,+0,1,0,,,0 0 0 0 1 1 1 0 0 1,1,0,+0,1,0,,,0 0 0 0 0 1 1 1 0 0 1,1,+x*,+0,,,0 1 0 0 1 1 0,,,0 1 0
43、 1 0 0,1,0,,,0 0 1 0 1 0 0,1 1 0 0 1,原码两位乘:,部分积 乘数,y*Cj 0 0 0,,,0 0 0 0 0 0 0 0,,,1 0 0 0,1 1,0 +1 1 1,,,1 0 1 1 0 1 +-x*,补,1 1 1,,,1 0 1 1 0 1 1,2 1 1 1,,,1 1 1 0 1 1 0 1 0 0,,,1 0,0 0,+,0 0 0,,,0 1 0 0 1 1,+x*0 0 0,,,0 0 1 1 1 0 0,2 0 0 0,,,0 0 0 0 1 1 1,0 0 1 0 0,,,1 0,+0 0 0,,,1 0 0 1 1 0,+2x*0
44、0 0,,,1 0 1 0 0 1,0,2 0 0 0,,,0 0 1 0 1 0 0 1,1,0 0 1,0 0,,,+0,结果同一位乘,,x,y=0,,,001 010 011 001,补码一位乘:,部分积 乘数,y,补,y,n+1,0 0,,,0 0 0 0 0 0 0,,,1 0 0 0 1,1 0,+1 1,,,1 0 1 1 0 1 +-x,补,1 1,,,1 0 1 1 0 1,1,1 1,,,1 1 0 1 1 0 1 0,,,1 0 0 0,1 1,+0,1,1 1,,,1 1 1 0 1 1 0 1 0,,,1 0 0,0 1,+0 0,,,0 1 0 0 1 1 +x,补
45、0 0,,,0 0 1 1 1 0,1 0 0,,,0 0 0 1 1 1 0,0 1 0,,,1 0,0 0,+0,1 0 0,,,0 0 0 0 1 1 1 0,0 1 0,,,1,0 0,+0,1 0 0,,,0 0 0 0 0 1 1 1 0,0 1 0,,,1 0,+,1 1,,,1 0 1 1 0 1 +-x,补,1 1,,,1 0 1 1 1 0,1,1 1,,,1 1 0 1 1 1 0,1 1 0,0 1,0,,,1,+0 0,,,0 1 0 0 1 1 +x,补,0 0,,,0 0 1 0 1 0,0,1 1 0,0 1,0,注:整数乘此位要省。,补码两位乘:,部分积 乘
46、数,y,n+1,0 0 0,,,0 0 0 0 0 0 0 0,,,1 0 0 0,1 1 0,+1 1 1,,,1 0 1 1 0 1 +-x,补,1 1 1,,,1 0 1 1 0 1,2,1 1 1,,,1 1 1 0 1 1 0 1 0 0,,,1 0,0 0 1,+0 0 0,,,0 1 0 0 1 1 +x,补,0 0 0,,,0 0 1 1 1 0,2 0 0 0,,,0 0 0 0 1 1 1 0,0 1 0 0,,,1 0 0,+,1 1 1,,,0 1 1 0 1 0 +-2x,补,1 1 1,,,0 1 1 1 0 1,2 1 1 1,,,1 1 0 1 1 1 0 1
47、1 0,0 1,0 0,,,1,+0 0 0,,,0 1 0 0 1 1 +0 0 0 0,,,0 0 1 0 1 0,0 1 1 0,0 1,0 0,省,结果同补码一位乘,,x,y=0,001 010 011 001,(,4,),x=0.110 11,,,y=-0.111 01 x*=x,原,=,x,补,=,0.110 11 y,原,=1.111 01,,,y*=0.111 01,y,补,=1.000 11,-x*,补,=-x,补,=1.001 01 2x*=2x,补,=01.101 10 -2x*,补,=-2x,补,=10.010 10,x,0,=0,,,y,0,=1,,,z,0,=x,0
48、y,0,=0,1=1,x*,y*=0.110 000 111 1,xy,原,=1.,110 000 111 1 xy,补,=1.,001 111 000 10,x,y=-0.,110 000 111 1,运算过程如下:,原码一位乘:,部分积 乘数,y*,0.0 0 0 0 0 .1 1 1 0,1,+x*,+,0.1 1 0 1 1 0.1 1 0 1 1,1 0.0 1 1 0 1 1,.1 1 1,0,+0,1 0.0 0 1 1 0 1 1,.1 1,1,+x*,+0.1 1 0 1 1 1.0 0 0 0 1,1 0.1 0 0 0 0 1 1 1 .1,1,+,x*,+0.,1 1
49、 0 1 1,1.0 1 0 1 1,1 0.1 0 1 0 1 1 1 1 1.1 +,x*,+0.,1 1 0 1 1 1.1 0 0 0 0,1 0.1 1 0 0 0 0 1 1 1 1,原码两位乘:,部分积 乘数,y*Cj 0 0 0.0 0 0 0 0 0.1 1 1,0 1,0 +0 0 0.1 1 0 1 1 +x*0 0 0.1 1 0 1 1 0,2 0 0 0.0 0 1 1 0 1 1 0.1,1 1,+,1 1 1.0 0 1 0 1,+-x*,补,1 1 1.0 1 0 1 1 1,2 1 1 1.1 1 0 1 0,1 1 1 1 .,0 1,+0 0 1.1 0
50、 1 1 0,+2x*0 0 1.1 0 0 0 0,0,1 0 0 0.1 1 0 0 0 0 1,1 1 1,0.,+0,结果同一位乘,,x,y=-0.,110 000 111 1,补码一位乘:,部分积 乘数,y,补,y,n+1,0 0.0 0 0 0 0 1.0 0 0 1,1 0,+1 1.0 0 1 0 1 +-x,补,1 1.0 0 1 0 1,1,1 1.1 0 0 1 0 1 1.0 0 0,1 1,+0,1,1 1.1 1 0 0 1 0 1 1.0 0,0 1,+0 0.1 1 0 1 1 +x,补,0 0.1 0 1 0 0,1 0 0.0 1 0 1 0 0,0 1 1