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?
0100 0001 0100 0101 0100 1101 0101 1001 is the binary representation of a positive 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:
* Not the case - the number is positive *
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
0 227
0 226
0 225
0 224
1 223
0 222
1 221
0 220
0 219
0 218
1 217
0 216
1 215
0 214
1 213
0 212
0 211
1 210
1 29
0 28
1 27
0 26
1 25
0 24
1 23
1 22
0 21
0 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0100 0001 0100 0101 0100 1101 0101 1001(2) =
(0 × 231 + 1 × 230 + 0 × 229 + 0 × 228 + 0 × 227 + 0 × 226 + 0 × 225 + 1 × 224 + 0 × 223 + 1 × 222 + 0 × 221 + 0 × 220 + 0 × 219 + 1 × 218 + 0 × 217 + 1 × 216 + 0 × 215 + 1 × 214 + 0 × 213 + 0 × 212 + 1 × 211 + 1 × 210 + 0 × 29 + 1 × 28 + 0 × 27 + 1 × 26 + 0 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 1 × 20)(10) =
(0 + 1 073 741 824 + 0 + 0 + 0 + 0 + 0 + 16 777 216 + 0 + 4 194 304 + 0 + 0 + 0 + 262 144 + 0 + 65 536 + 0 + 16 384 + 0 + 0 + 2 048 + 1 024 + 0 + 256 + 0 + 64 + 0 + 16 + 8 + 0 + 0 + 1)(10) =
(1 073 741 824 + 16 777 216 + 4 194 304 + 262 144 + 65 536 + 16 384 + 2 048 + 1 024 + 256 + 64 + 16 + 8 + 1)(10) =
1 095 060 825(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
0100 0001 0100 0101 0100 1101 0101 1001(2) = 1 095 060 825(10)
The number 0100 0001 0100 0101 0100 1101 0101 1001(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
0100 0001 0100 0101 0100 1101 0101 1001(2) = 1 095 060 825(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.