| 摘要 |
PROBLEM TO BE SOLVED: To provide a CR oscillation circuit having the function of adjusting a frequency of the CR oscillation circuit, without requiring a trimming fuse and a pad for fuse. SOLUTION: A CR oscillation circuit is provided with a counter 102 detecting a frequency of an output signal of a CR oscillation circuit 107, a comparison determination circuit 103 comparing count of the counter with data prepared in a comparing data register circuit 104 and determining whether the frequency expected is obtained, an up and down counter 105 fluctuating the count by the result of the comparison determining circuit, a decoder circuit 106 decoding the output of the up and down counter, and a function of adjusting on/off of a switch transistor 108 by the output signal of the decoder circuit and adjusting the frequency of the CR oscillator. COPYRIGHT: (C)2005,JPO&NCIPI
|
