The watch dog circuit compares a second reference voltage with a voltage exhibited by the first reset signal, and provides output of a second reset signal to the controller to reset the controller in dependence upon the comparison between the second reference voltage and {TAIL ~ the voltage} exhibited by {HEAD ~ the first reset signal} 
The watch dog circuit compares a second reference voltage with a voltage exhibited by the first reset signal , and provides output of a second reset signal to the controller to reset the controller in dependence upon the comparison between the second reference voltage and { TAIL ~ the voltage } exhibited by { HEAD ~ the first reset signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD