| 摘要 |
PROBLEM TO BE SOLVED: To obtain a highly precise clock signal by output of a first oscillator circuit without waiting for starting of a second oscillator circuit.SOLUTION: The clock system 1 includes: a CR oscillator circuit 11; a crystal oscillator circuit 12; and a trimming circuit 15. The CR oscillator circuit 11 generates a clock CLK 1 to be supplied to an internal circuit 17. The crystal oscillator circuit 12 is used for adjustment of an oscillation frequency of the CR oscillator circuit 11. The trimming circuit 15 adjusts the oscillation frequency of the CR oscillator circuit 11 on the basis of a detection result of oscillation frequency difference between the CR oscillator circuit 11 and the crystal oscillator circuit 12. |
