| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling a Galois field multiplier which can perform logical exclusive OR operation with a small number of instruction cycles, while eliminating the need for expanding a circuit scale. SOLUTION: A bit string Di of a Galois field element as the CRC value of data D3 of k1 to k2 bytes is found (ST11). An order M, corresponding to the number K of bytes from (k2+1) to the final byte, is found, and a reference order and a residual order R is found from the order M (ST12). After the bit string Di is set in a CRC encoder, the CRC encoder is shifted by an amount, corresponding to the remaining order R (ST13). Subsequently, bit shifts and logical exclusive-OR operations between a bit string Sj of the reference order and an operation result found by the shifting operation of the CRC encoder are carried out (ST14). COPYRIGHT: (C)2004,JPO
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