2’s Complement Representation for Integers

Key is to use largest positive binary numbers to represent negative numbers

Obtain negative number by subtracting large constant

i = -an-1*2n-1 + an-2*2 n-2 + ... a0*20

6-bit examples:

0101102 = 2210 ; 1010102 = -2210

010 = 0000002; 110 = 0000012; -110 = 1111112

0001 1

0010 2

0011 3

0100 4

0101 5

0110 6

0111 7

1000 -8

1001 -7

1010 -6

1011 -5

1100 -4

1101 -3

1110 -2

1111 -1

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