| 摘要 |
PURPOSE:To simplify the constitution of a device and to decode a coded word in a short time, by obtaining the 1st, 2nd and 3rd syndrome through the use of a shift register from the coded word of 3-error correction BCH and correcting the error with the primitive element of the Galois field of the element. CONSTITUTION:The 1st, 2nd and 3rd syndromes A1, A2 and A3 are outputted from the 1st, 2nd and 3rd syndrome producing circuits 102, 104 and 106 by using a data buffer 101 consisting of shift registers for an input data (a). Further, a correction condition discriminating circuit 108 discriminates if A1<3>+A2 is zero and a bit number (t) taking S1=A1+alpha<n-t> as zero is applied to a selection circuit 117. The 1st and 2nd error detection circuits 115 and 116 discriminate if A1<3>+A2not equal to 0, bit trains S1, S2 and S3 are taken as equation 1, an input bit corresponding to values t1, t2, t3, up to three, of a bit number (t) giving EL(t) is inverted, the others are outputted as they are, and three errors are corrected at an error correction circuit 118. |
