PMAC Quick Reference Guide A faster than 20 MHz PMAC will perform calculations faster, in proportion to the corresponding clock rate increase. In general, a clock rate increase is used to increase the real time interrupt (RTI) share of the total computational time available. These cases include applications where large move calculations are involved (small-moves contouring), maintaining the same servo-loop rate and therefore the same control performance. 20 MHz PMAC, 8 commutated servo-motors 20 MHz PMAC, 8 non-commutated servo-motors Servo Cycle Phase Cycle Real-Time Interrupt 40 MHz PMAC, 8 commutated servo-motors 40 MHz PMAC, 8 non-commutated servo-motors Background Cycle 12 Introduction