| 摘要 |
PURPOSE:To control the width of a window pulse according to variation in clock bit intervals, by deciding the width of the window pulse on the basis of the mean value of time intervals of preceding clock bits. CONSTITUTION:When a detection input signal is transmitted to an input terminal IN and a timer TM2 measure a time interval twn-1, the 1st latch circuit 3 latches the value of a time interval twn-2 and the 2nd circuit 4 latches a time interval twn-3. An operating device 5 decides on the width tDn-1 of a window pulse by multiplying the mean value of said two time intervals by a specific coefficient. A window pulse control circuit 6 generates a window pulse WP(td) having the width tDn-1 calculated by the operating device 5 at an output terminal P while regarding a fall of a succeeding clock bit Cbn-2 transmitted from a terminal IN as a starting point, and supplies the pulse to a sampling circuit 7. At the other output terminal of the circuit 6, the inversion output of the output at the terminal P appears to reset the timer 2 through an AND circuit 1. The same operation is carried out repeatedly thereafter. |
