A synchronization control apparatus includes a counter that carries out a counting and outputs resulting count information, a timeout time holder that holds a predetermined timeout time and outputs the timeout time, a comparator that compares the count information output from the counter and the timeout time output from the timeout time holder, a synchronization controller that monitors a synchronization between a first processor and a second processor by comparing an output from the first processor and an output from the second processor and starts a counting, when a mis-match of the outputs from the first processor and the second processor is detected and wherein the comparator detects that the count information and the timeout time match, the comparator stops either the first processor or second processor in which a synchronization delay has occurred.