| 摘要 |
Circuitry for detecting and correcting errors in data words occurring in Reed-Solomon coded blocks contains a plurality of stages. One stage constructs syndromes in the data flowing through the blocks. Another stage detects erasures in the syndromes. Another stage applies a Euclid's algorithm with Ts(x)={Qs-1(x)xTs-1(x)}+Ts-2(x), Rs(x)={Qs-1(x)xRs-1(x)}+Rs-2(x), and I Qs-1(x)=Rs-2(x)/Rs-1(x) wherein Ts(x), Rs(x), and Qs-1(x) are polynomials representing the position of the error, its value, and a provisional value respectively, and Rs(x) and Ts(x) can be normalized with a minimal coefficient Ts(0)= delta such that R(x)=Rs(xi/ delta and T(x)=Ts(x)/ delta . Another stage detects error positions Xk and values Yk by conducting a Chien zero-root search in conjunction with <IMAGE> wherein T'(Xk) is the first derivative of T at a place xk. Another stage uses the accordingly calculated error positions Xk and values Yk to correct signal-duration matched data words in a currently occurring Reed-Solomon coded block. when the two counts are equal. An exclusive-OR stage has one input terminal which receives the error value at the top of the fourth stack in accordance with the control signal, another input terminal which receives the signal-duration matched data words, and an output terminal that emits corrected data words.
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