Nxp 4000 series logic devices nxp hef4040bt the hef4040b is a 12 stage binary ripple counter with a clock input cp an overriding asynchronous master reset input mr and twelve fully buffered outputs q0 to q11 the counter advances on the high to low transition of cp a high on mr clears all counter stages and forces all outputs low independent of cp each counter stage is a static toggle flip flop the clock input is highly tolerant of slow rise and fall times due to its schmitt trigge