A simulation control program receives a hardware description language (HDL) model including design entities and count event registers. Each count event registers is associated with a respective instance of an event. The count event registers include first and second registers for counting occurrences of a same replicated event generated within different instances of a same design entity having a same hierarchical level within the HDL model. The simulation control program also receives a correlation data structure indicating which count event registers are associated with instances of the same replicated event. During simulation processing, each of the count event registers maintains a respective count value representing a number of times an associated event instance occurs. The simulation control program sums count values of the first and second count event registers in accordance with the correlation data structure and outputs a count event data packet containing the aggregate count value.