HD64F38602R Datasheet, PDF (245/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 13 Asynchronous Event Counter (AEC)
Section 13 Asynchronous Event Counter (AEC)
The asynchronous event counter (AEC) is an event counter that is incremented by external event
clock or internal clock input. Figure 13.1 shows a block diagram of the asynchronous event
counter.
13.1 Features
• Can count asynchronous events
Can count external events input asynchronously without regard to the operation of system
clocks (φ) or subclocks (φ_SUB).
• Can be used as two-channel independent 8-bit event counter or single-channel independent 16-
bit event counter.
• Event/clock input is enabled when IRQAEC goes high or event counter PWM output
(IECPWM) goes high.
• Both rising and falling edge sensing can be used for IRQAEC or event counter PWM output
(IECPWM) interrupts. When the asynchronous counter is not used, they can be used as
independent interrupts.
• When an event counter PWM is used, event clock input enabling/disabling can be controlled at
a constant cycle.
An event counter PWM can be output to the AECPWM pin.
• Selection of four clock sources
Three internal clocks (φ/2, φ/4, or φ/8) or external event can be selected.
• Both rising and falling edge counting is possible for the AEVL and AEVH pins.
• Counter resetting and halting of the count-up function can be controlled by software.
• Automatic interrupt generation on detection of an event counter overflow
• Use of module standby mode enables this module to be placed in standby mode independently
when not used. (The asynchronous event counter is halted as the initial value. For details, refer
to section 5.4, Module Standby Function.)
Rev. 3.00 May 15, 2007 Page 213 of 516
REJ09B0152-0300