9.7
Asynchronous Event Counter (AEC)
9.7.1
Overview
The asynchronous event counter is incremented by external event clock or internal clock input.
Features
Features of the asynchronous event counter are given below.
• Can count asynchronous events
Can count external events input asynchronously without regard to the operation of base clocks
φ and φ
.
SUB
The counter has a 16-bit configuration, enabling it to count up to 65536 (2
• Can also be used as two independent 8-bit event counter channels.
• Can be used as single-channel independent 16-bit event counter.
• Event/clock input is enabled only when IRQAEC is high or event counter PWM output
(IECPWM) is high.
• Both edge sensing can be used for IRQAEC or event counter PWM output (IECPWM)
interrupts. When the asynchronous counter is not used, independent interrupt function use is
possible.
• When an event counter PWM is used, event clock input enabling/disabling can be performed
automatically in a fixed cycle.
• External event input or a prescaler output clock can be selected by software for the ECH and
ECL clock sources. φ/2, φ/4, or φ/8 can be selected as the prescaler output clock.
• Both edge counting is possible for AEVL and AEVH.
• Counter resetting and halting of the count-up function controllable by software
• Automatic interrupt generation on detection of event counter overflow
• Use of module standby mode enables this module to be placed in standby mode independently
when not used.
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Section 9 Timers
) events.
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