Being the deadlock detector which detects the deadlock

摘要

PROBLEM TO BE SOLVED: To provide a deadlock detection circuit for accurately detecting a deadlock state without erroneous detection.;SOLUTION: The deadlock detection circuit detects the deadlock state of a PLL circuit and includes: a PLL incorporated frequency divider for frequency-dividing the output signals of the voltage controlled oscillator of the PLL circuit and outputting a first frequency division clock; a feedback frequency divider for frequency-dividing the output signals of the voltage controlled oscillator and outputting a second frequency division clock to be a feedback clock to the phase comparator of the PLL circuit; and an erroneous lock detection circuit for outputting a determination signal indicating whether or not it is in the deadlock state on the basis of the clock number of the second frequency division clock included in a prescribed period determined by the cycle of the first frequency division clock.;COPYRIGHT: (C)2010,JPO&INPIT