| 摘要 |
<p>PURPOSE:To control time even if a reference time generation signal is stopped by usually controlling time based on an external interruption signal by means of a reference time signal and controlling time by means of switching to internal timer circuits when the time interval of the generation of the interruption signal comes to be more than prescribed time. CONSTITUTION:The internal timer circuits 3 are provided for respective microcomputers 1. Time is usually controlled based on the external interruption signal by the reference time signal 4, and a system is switched to the internal timer circuits 3 when the time interval of the generation of the interruption signal comes to be more than prescribed time to control time. Thus, all the microcomputers 1 which commonly use the reference time signal 4 and control time can control time even if abnormality occurs in a reference time generation part 2 and the reference time generation signal 4 transmitted to respective microcomputers 1 is stopped.</p> |
