| 摘要 |
PURPOSE:To surely prevent a count error by providing a detecting means and correcting a count number based on whether an asynchronous pulse is inputted before a reference clock pulse or after the reference clock pulse when it is detected that the asynchronous pulse is inputted within prescribed time from the reference clock pulse. CONSTITUTION:When +CLEAR is inputted from an input device 12 to a counter 14, the count value of the counter 14 is initialized to '0', when +CNTEN asynchronous with the reference clock pulse is inputted to the counter 14, the counter 14 counts the pulse number of a reference clock pulse signal -CLOCK to be inputted from a clock pulse generating circuit 10, and when +CNTSTP is inputted to the counter 14, the counter 14 completes the counting. When the detecting means composed of tooth-shaped wave generating circuits 16A and 16B to generate a tooth-shaped wave synchronizing with -CLOCK or having the prescribed phase difference with -CLOCK and A/D converters 18A and 18B to hold the output voltage of the tooth-shaped wave generating circuits when +CLEAR is inputted judges that +CLEAR is inputted within the prescribed time, the count number is corrected for a prescribed set value based on whether +CLEAR is inputted before -CLOCK or after -CLOCK. |
