| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the following problem of a conventional optical transmission control circuit: when a digital value is abnormal, an error notification is output to a host device and updating of the digital value is stopped, therefore, even if the digital value further exceeds a threshold at a stage where the host device reads the digital value of the optical transmission control circuit, the digital value exceeding the threshold is not updated in a digital value storage section and a latest abnormal value cannot be obtained. <P>SOLUTION: A maximum value/minimum value storage section 12 stores a maximum value and/or a minimum value of a digital value converted by an A/D conversion unit 30, respectively, and a control section controls a storage operation of the maximum value and/or the minimum value into the maximum value/minimum value storage unit and outputs the maximum value and/or the minimum value to a host device. Thus, when the digital value further exceeds the threshold at the stage where the host device reads the digital value of the optical transmission control circuit, the digital value is updated in the maximum value/minimum value storage section 12, and consequently the latest abnormal value can be extracted. <P>COPYRIGHT: (C)2008,JPO&INPIT |
