| y in Hex | y in Binary | ~y in Binary | ~y in Hex |
|---|---|---|---|
| 0x0 | 0000 | 1111 | 0xF |
| 0x1 | 0001 | 1110 | 0xE |
| 0x2 | 0010 | 1101 | 0xD |
| 0x3 | 0011 | 1100 | 0xC |
| 0x4 | 0100 | 1011 | 0xB |
| 0x5 | 0101 | 1010 | 0xA |
| 0x6 | 0110 | 1001 | 0x9 |
| 0x7 | 0111 | 1000 | 0x8 |
| 0x8 | 1000 | 0111 | 0x7 |
The sum of the hex digit y and its 1's complement is always 0xF or 15 in decimal!