Triplet decoding circuit and triplet decoding method

摘要

A triplet decoding method capable of decoding operation in a short time is provide, in which a triplet data Y is defined as Y=9M1+3M2+ M3. A first decimal value -9 is subtracted from a decimal value Y to generate a first subtraction result. A second decimal value -18 is subtracted from the value of Y to generate a second subtraction result. A third decimal value -27 is subtracted from Y to generate a third subtraction result. Then, whether each of the first, second, and third subtraction results has a negative polarity is judged to know M1. A provisional triplet data Y' is calculated by subtracting 9M1 from Y. Further, the first value -9 is subtracted from a value of Y' to generate a fourth subtraction result. The second value -18 is subtracted from the value of Y' to generate a fifth subtraction result. The third value -27 is subtracted from the value of Y' to generate a sixth subtraction result. Then, whether each of the fourth, fifth, and sixth subtraction results has a negative polarity or not is judged to know the second decimal number M2. The third decimal number M3 is calculated by substracting a value of 3M2 from the value of the provisional triplet data Y'.