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?
1010 0000 1010 0000 1010 0000 1010 0000 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:
!(1010 0000 1010 0000 1010 0000 1010 0000) = 0101 1111 0101 1111 0101 1111 0101 1111
3. Map the unsigned binary number's digits versus the corresponding powers of 2 that their place value represent:
231
0 230
1 229
0 228
1 227
1 226
1 225
1 224
1 223
0 222
1 221
0 220
1 219
1 218
1 217
1 216
1 215
0 214
1 213
0 212
1 211
1 210
1 29
1 28
1 27
0 26
1 25
0 24
1 23
1 22
1 21
1 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0101 1111 0101 1111 0101 1111 0101 1111(2) =
(0 × 231 + 1 × 230 + 0 × 229 + 1 × 228 + 1 × 227 + 1 × 226 + 1 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 1 × 220 + 1 × 219 + 1 × 218 + 1 × 217 + 1 × 216 + 0 × 215 + 1 × 214 + 0 × 213 + 1 × 212 + 1 × 211 + 1 × 210 + 1 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20)(10) =
(0 + 1 073 741 824 + 0 + 268 435 456 + 134 217 728 + 67 108 864 + 33 554 432 + 16 777 216 + 0 + 4 194 304 + 0 + 1 048 576 + 524 288 + 262 144 + 131 072 + 65 536 + 0 + 16 384 + 0 + 4 096 + 2 048 + 1 024 + 512 + 256 + 0 + 64 + 0 + 16 + 8 + 4 + 2 + 1)(10) =
(1 073 741 824 + 268 435 456 + 134 217 728 + 67 108 864 + 33 554 432 + 16 777 216 + 4 194 304 + 1 048 576 + 524 288 + 262 144 + 131 072 + 65 536 + 16 384 + 4 096 + 2 048 + 1 024 + 512 + 256 + 64 + 16 + 8 + 4 + 2 + 1)(10) =
1 600 085 855(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1010 0000 1010 0000 1010 0000 1010 0000(2) = -1 600 085 855(10)
The number 1010 0000 1010 0000 1010 0000 1010 0000(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1010 0000 1010 0000 1010 0000 1010 0000(2) = -1 600 085 855(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.