| 摘要 |
PURPOSE:To attain miniaturization by dividing n bits into plural blocks, decoding each divided block tentatively and decoding a data word based on the combination of the results to decrease the capacity of a ROM. CONSTITUTION:A recovered code word is stored in the unit of code words in an S/P converter 1 and a 12-bit D flip-flop 2. The head bit of a code word is given to one input of an exclusive OR gate 4 via an inverter 3. Further, the 3rd-6th bits and the head bit of the 2nd block are given to the other input. The 4 bits relating to the 1st block are fed to a ROM5 among the outputs of the gate 4 to output a 2-bit value R1. Then the head bit of the 2nd block is given to one input of an exclusive OR gate 6. Further, the 2nd-6th bits of the 2nd block are fed to the other input. Then a 5-bit bit pattern is fed to a ROM7 to output a 3-bit value R2. In giving the tentatively decoded values R1, R2 to a ROM8, a decoded value corresponding to the R1, R2 is outputted.
|
