| 摘要 |
PURPOSE:To shorten a detecting time by transferring the value of a flip-flop in a first step to a flip-flop in a second step when resetting a register after a state change is detected. CONSTITUTION:The state change of a direction signal is observed over a wide range and only when there are plural state changes, the count of a count circuit 35 is executed. When resetting a shift register 28 after these plural state changes are detected, the flip-flops after the second step and set or reset corresponding to the output of a flip-flop 29 in the first step of the shift register 28. Therefore, the data of the flip-flop 29 requiring no erasion can be transferred to a flip-flop 30 in the second step. Thus, a time for lock detection can be shortened. |
