A read and write, 32-bit register for each of the four event counters and cycle counter. The cycle counter counts either every CCI-400 clock cycle, or every 64 clock cycles, depending on the PMCR bit[3].

You can reset all event counter values to zero by writing a 1 to the PMCR bit[1] and reset all clock counter values by writing a 1 to PMCR bit[2].