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 0100 0100 1111 1111 1111 1111 1010 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 0100 0100 1111 1111 1111 1111 1010) = 0011 1011 1011 0000 0000 0000 0000 0101
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
0 225
1 224
1 223
1 222
0 221
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
0 26
0 25
0 24
0 23
0 22
1 21
0 20
1
4. Multiply each bit by its corresponding power of 2 and add all the terms up.
0011 1011 1011 0000 0000 0000 0000 0101(2) =
(0 × 231 + 0 × 230 + 1 × 229 + 1 × 228 + 1 × 227 + 0 × 226 + 1 × 225 + 1 × 224 + 1 × 223 + 0 × 222 + 1 × 221 + 1 × 220 + 0 × 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 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 1 × 22 + 0 × 21 + 1 × 20)(10) =
(0 + 0 + 536 870 912 + 268 435 456 + 134 217 728 + 0 + 33 554 432 + 16 777 216 + 8 388 608 + 0 + 2 097 152 + 1 048 576 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 4 + 0 + 1)(10) =
(536 870 912 + 268 435 456 + 134 217 728 + 33 554 432 + 16 777 216 + 8 388 608 + 2 097 152 + 1 048 576 + 4 + 1)(10) =
1 001 390 085(10)
5. If needed, adjust the sign of the integer number by the first digit (leftmost) of the signed binary:
1100 0100 0100 1111 1111 1111 1111 1010(2) = -1 001 390 085(10)
The number 1100 0100 0100 1111 1111 1111 1111 1010(2), signed binary in one's (1's) complement representation, converted and written as an integer in decimal system (base ten):
1100 0100 0100 1111 1111 1111 1111 1010(2) = -1 001 390 085(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.