| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an oscillation circuit operation state detecting circuit for detecting an operation state of an oscillation circuit in a short time. <P>SOLUTION: Between a power supply terminal of VDD and a power supply terminal of VSS, transistors MP1 and MN1 having a node N1 as a common connection point are connected in series and transistors MP2 and MN2 having a node N2 as a common connection point are connected in series. A capacity C1 is connected between the nodes N1 and N2. An input side of an NOR1 is connected to the nodes N1 and N2. A power source I1 is connected to the transistors MP1 and MN1 in series, and a power source I2 is connected to the transistors MP2 and MN2 in series. An OFF-resistance of the transistors MN1 and MN2 is made to be lower than that of the transistors MP1 and MP2. The oscillation circuit operation state detecting circuit turns on the transistors MN1 and MN2 and turns off the transistors MP2 and MN1 when an oscillation clock signal of an oscillation circuit is at a first logic level, and vice versa at a second logic level. <P>COPYRIGHT: (C)2012,JPO&INPIT |
