IGACPMX01A is an on-chip performance monitor which contains a maximum of 32 customized multiple ring oscillators. This macro is one sensor unit of chip performance and process monitor system. The controller, IGDOMC002A, will control this macro to read out the frequency of ring oscillators. The SoC system can use this frequency of different ring oscillators to come out with one formula to be the reference of chip performance or critical path timing, and the control system can be implemented to perform Adaptive Voltage Scaling (AVS) and Dynamic Voltage and Frequency Scaling (DVFS) of SoC chip. Besides customized ring oscillator, the macro also supports one clone path of chip performance for monitoring correlation.