Aiken code
| Aiken code | |
|---|---|
| Number of digits | 4th |
| assessable | Yes |
| steadily | No |
| Weight | 0… 4 |
| Minimum distance | 1 |
| Maximum distance | 4th |
| Hamming distance | 1… 4 |
| redundancy | 0.7 |
The Aiken code is a complementary BCD code . A tetrad of four bits is assigned to each of the decimal digits from 0 to 9 according to the following table . The code was developed by Howard Hathaway Aiken and is still used today in digital watches , pocket calculators and similar devices.
State diagram Aiken code in hexadecimal coding
The Aiken code differs from the BCD code in that in the Aiken code the 4th digit is not weighted with 8 as with the BCD code, but with 2.
The Aiken code has the following weighting: 2–4–2–1
One might think that double coding is possible for a number, e.g. B. 1011 and 0101 could represent 5. However, one ensures that the digits 0 to 4 are mirror images of the digits 5 to 9.
| Aiken code example | ||||
|---|---|---|---|---|
|
Decimal digit |
Aiken- coded |
BCD coded |
||
| 0 | 0 0 0 0 | 0 0 0 0 | ||
| 1 | 0 0 0 1 | 0 0 0 1 | ||
| 2 | 0 0 1 0 | 0 0 1 0 | ||
| 3 | 0 0 1 1 | 0 0 1 1 | ||
| 4th | 0 1 0 0 | 0 1 0 0 | ||
| 5 | 1 0 1 1 | 0 1 0 1 | ||
| 6th | 1 1 0 0 | 0 1 1 0 | ||
| 7th | 1 1 0 1 | 0 1 1 1 | ||
| 8th | 1 1 1 0 | 1 0 0 0 | ||
| 9 | 1 1 1 1 | 1 0 0 1 | ||