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 0010 1000 0111 1111 1111 1001 1101 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 0010 1000 0111 1111 1111 1001 1101) = 0011 1101 0111 1000 0000 0000 0110 0010
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
1 226
1 225
0 224
1 223
0 222
1 221
1 220
1 219
1 218
0 217
0 216
0 215
0 214
0 213
0 212
0 211
0 210
0 29
0 28
0 27
0 26
1 25
1 24
0 23
0 22
0 21
1 20
0
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0011 1101 0111 1000 0000 0000 0110 0010(2) =
(0 × 231 + 0 × 230 + 1 × 229 + 1 × 228 + 1 × 227 + 1 × 226 + 0 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 1 × 221 + 1 × 220 + 1 × 219 + 0 × 218 + 0 × 217 + 0 × 216 + 0 × 215 + 0 × 214 + 0 × 213 + 0 × 212 + 0 × 211 + 0 × 210 + 0 × 29 + 0 × 28 + 0 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 0 × 23 + 0 × 22 + 1 × 21 + 0 × 20)(10) =
(0 + 0 + 536 870 912 + 268 435 456 + 134 217 728 + 67 108 864 + 0 + 16 777 216 + 0 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 64 + 32 + 0 + 0 + 0 + 2 + 0)(10) =
(536 870 912 + 268 435 456 + 134 217 728 + 67 108 864 + 16 777 216 + 4 194 304 + 2 097 152 + 1 048 576 + 524 288 + 64 + 32 + 2)(10) =
1 031 274 594(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1100 0010 1000 0111 1111 1111 1001 1101(2) = -1 031 274 594(10)
The number 1100 0010 1000 0111 1111 1111 1001 1101(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1100 0010 1000 0111 1111 1111 1001 1101(2) = -1 031 274 594(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.