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?
1100 1010 1111 1110 1010 1010 0101 0001 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:
!(1100 1010 1111 1110 1010 1010 0101 0001) = 0011 0101 0000 0001 0101 0101 1010 1110
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
1 227
0 226
1 225
0 224
1 223
0 222
0 221
0 220
0 219
0 218
0 217
0 216
1 215
0 214
1 213
0 212
1 211
0 210
1 29
0 28
1 27
1 26
0 25
1 24
0 23
1 22
1 21
1 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0011 0101 0000 0001 0101 0101 1010 1110(2) =
(0 × 231 + 0 × 230 + 1 × 229 + 1 × 228 + 0 × 227 + 1 × 226 + 0 × 225 + 1 × 224 + 0 × 223 + 0 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 0 × 218 + 0 × 217 + 1 × 216 + 0 × 215 + 1 × 214 + 0 × 213 + 1 × 212 + 0 × 211 + 1 × 210 + 0 × 29 + 1 × 28 + 1 × 27 + 0 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 0 × 20)(10) =
(0 + 0 + 536 870 912 + 268 435 456 + 0 + 67 108 864 + 0 + 16 777 216 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 65 536 + 0 + 16 384 + 0 + 4 096 + 0 + 1 024 + 0 + 256 + 128 + 0 + 32 + 0 + 8 + 4 + 2 + 0)(10) =
(536 870 912 + 268 435 456 + 67 108 864 + 16 777 216 + 65 536 + 16 384 + 4 096 + 1 024 + 256 + 128 + 32 + 8 + 4 + 2)(10) =
889 279 918(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1100 1010 1111 1110 1010 1010 0101 0001(2) = -889 279 918(10)
The number 1100 1010 1111 1110 1010 1010 0101 0001(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1100 1010 1111 1110 1010 1010 0101 0001(2) = -889 279 918(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.