The CPU clock is used for performance measurement by a Performance Measurement event (see "2.16.1 Measure the performance in a section" for details).

If "Clock cycle", "Non-interrupt cycle", or "Interrupt disable cycle of DI/EI" is set as a measurement item (see "Detailed Settings of Performance Measurement dialog box [Full-spec emulator][E1][E20]"), the number of CPU cycles is measured. If any other item is set as a measurement item, the number of counts is measured. The measurable range is from 0 to 4294967295.