补码的加法运算.图中的两个例子是错误的,
1个回答

第1题:

x =9/16 =1001b/16d =0.1001b , (将1001b右移4位)

y =11/16 =1011b/16 =0.1011b, (将1011b右移4位)

设字长8位:

[x]补 =0000.1001b

[y]补 =0000.1011b (+

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[x+y]补 =0001.0100b

x+y = 10100b/16 = 20/16,(将 1.0100b左移4位)

第2题:

A = -97d = -110 0001b, [A]补 =1001 1111b

-B = -41d = -10 1001b, [-B]补 =1101 0111b (+

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[A-B]补 =1 0111 0110b

Cs♁Cp = 1♁0 = 1 ,负溢出

(Cs是符号位的进位,Cp是最高数值位的进位,♁表示异或)

[A-B]反 = -0111 0101b

[A-B]原 = -1000 1010B

A-B = -1000 1010B = -138d