摘要 |
Where an N-bit input data is rotated together with a carry bit by an N-bit or more rotate count, the actual rotate count is obtained as a remainder or modulo of x/N+1 (x: rotate count; N: data bit length). The above remainder will not be obtained by simply masking shift signals. Therefore, the remainder is calculated at high speed through hardware including a subtrahend calculator section for calculating (N+1) (i) (i=0, 1, 2, . . . ) and a subtracter section for calculating {x-(N+1) (i)} to obtain a modulo or a remainder representative of an actual rotate count. |