| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to set a parameter value to a clock generating circuit from the outside at the time of the occurrence of trouble, while preventing an inappropriate parameter value from being set to the clock generating circuit during normal time.SOLUTION: When the level of a setting protection terminal 14 is in a predetermined level, a clock setting circuit 12 (a) causes a selector 15 to select a source clock before changing a parameter value in a clock generating circuit 11 with a parameter value set from the outside and stored in a register 16, and (b) causes the selector 15, after the clock generating circuit 11 starts generating clocks with the parameter value after the change, to select a clock generated by the clock generating circuit 11. |
