What are the steps to convert the signed binary in one's (1's) complement representation to an integer in decimal system (in base ten)?
1. Is this a positive or a negative number?
1101 0001 1111 0000 0000 0000 0101 0100 is the binary representation of a negative integer, on 32 bits (4 Bytes).
- In a signed binary in one's complement representation, the first bit (the leftmost) indicates the sign, 1 = negative, 0 = positive.
2. Get the binary representation of the positive (unsigned) number.
* Run this step only if the number is negative *
Flip all the bits of the signed binary in one's complement representation (reverse the digits) - replace the bits set on 1 with 0s and the bits on 0 with 1s:
!(1101 0001 1111 0000 0000 0000 0101 0100) = 0010 1110 0000 1111 1111 1111 1010 1011
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
231
0 230
0 229
1 228
0 227
1 226
1 225
1 224
0 223
0 222
0 221
0 220
0 219
1 218
1 217
1 216
1 215
1 214
1 213
1 212
1 211
1 210
1 29
1 28
1 27
1 26
0 25
1 24
0 23
1 22
0 21
1 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0010 1110 0000 1111 1111 1111 1010 1011(2) =
(0 × 231 + 0 × 230 + 1 × 229 + 0 × 228 + 1 × 227 + 1 × 226 + 1 × 225 + 0 × 224 + 0 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 1 × 219 + 1 × 218 + 1 × 217 + 1 × 216 + 1 × 215 + 1 × 214 + 1 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 0 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 0 + 536 870 912 + 0 + 134 217 728 + 67 108 864 + 33 554 432 + 0 + 0 + 0 + 0 + 0 + 524 288 + 262 144 + 131 072 + 65 536 + 32 768 + 16 384 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 0 + 32 + 0 + 8 + 0 + 2 + 1)(10) =
(536 870 912 + 134 217 728 + 67 108 864 + 33 554 432 + 524 288 + 262 144 + 131 072 + 65 536 + 32 768 + 16 384 + 8 192 + 4 096 + 2 048 + 1 024 + 512 + 256 + 128 + 32 + 8 + 2 + 1)(10) =
772 800 427(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1101 0001 1111 0000 0000 0000 0101 0100(2) = -772 800 427(10)
The number 1101 0001 1111 0000 0000 0000 0101 0100(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1101 0001 1111 0000 0000 0000 0101 0100(2) = -772 800 427(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.