Libaw-Craig code
| Libaw-Craig code | |
|---|---|
| Number of digits | 5 |
| steadily | Yes |
| redundancy | 1.7 |
The Libaw-Craig code (also called the Johnson code ) is a special 5-bit representation of a digit in the decimal system . It is the code used for the Johnson counter . As with the BCD code , it is a numeric code that individually binary- codes each digit of a decimal number . The code is continuous (sometimes referred to as one-step). In the inverted signal sequence, it corresponds to the digit coding as Morse code .
Coding
| value | presentation |
|---|---|
| 0 | 00000 |
| 1 | 00001 |
| 2 | 00011 |
| 3 | 00111 |
| 4th | 01111 |
| 5 | 11111 |
| 6th | 11110 |
| 7th | 11100 |
| 8th | 11000 |
| 9 | 10,000 |
Properties of the Libaw-Craig code
- The representation of the tens complement of a value is obtained simply by reversing the order of the five bits.
- The Libaw-Craig code, like the Gray code, is continuous , that is, the representation of a value and the value following it always differs in exactly one bit. Since the representations of 9 and 0 also differ in only one bit, the term “following value” here refers to the cyclical additive group of digits .
- In contrast to the Gray code, which is redundancy-free , the Libaw-Craig code is redundant ( R = 1.7). This of course provides a certain amount of error detection.
application
An up and down counter with the Libaw-Craig code can be easily set up with a 5-digit feedback shift register . Several such up and down counters can then be built up to form a decimal up and down decimal counter, which can be compared with a mechanical odometer.
Because of its continuity, the Libaw-Craig code is suitable for asynchronous 5-bit parallel signal sources such as B. coarse encoder for changing a single digit of a decimal number.