| 摘要 |
PROBLEM TO BE SOLVED: To prevent synchronization of a plurality of numerical values applied as random numbers and updated at intervals of prescribed period. SOLUTION: A random number updating process is executed every timer interruption, and an addition determining value and a random number determining value are registered in a table by the kind of random number. The kind of random number first registered in the table is used as an object of the process (S101). Four bits in the lower ranks in a refreshing register whose values are updated at shorter intervals than the timer interruption are the initial values of the addition values (S102), and the addition determining value is repeatedly subtracted from the addition values till the addition values become their addition determining values (S103 and S104). The number of times of the repetition varies according to the value extracted from the refreshing register. The calculated addition values are added to the present value of random number as the object of the process, and the value is used as the random number value after updated (S105-S108). If the random numbers which are not objects of the process remain, the kind of random number next registered in the table is used as the object for the process (S109), and the procedure is returned to the step S102. COPYRIGHT: (C)2005,JPO&NCIPI
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