Datasheet

Table Of Contents
Section 15 Asynchronous Event Counter (AEC)
Rev. 2.00 Jul. 04, 2007 Page 330 of 692
REJ09B0309-0200
15.4.3 IRQAEC Operation
When the ECPWME bit in AEGSR is 0, the ECH and ECL input clocks are enabled when
IRQAEC goes high. When IRQAEC goes low, the input clocks are not input to the counters, and
so ECH and ECL do not count. ECH and ECL count operations can therefore be controlled from
outside by controlling IRQAEC. In this case, ECH and ECL cannot be controlled individually.
IRQAEC can also operate as an interrupt source.
Interrupt enabling is controlled by IENEC2 in IENR1. When an IRQAEC interrupt is generated,
IRR1 interrupt request flag IRREC2 is set to 1. If IENEC2 in IENR1 is set to 1 at this time, an
interrupt request is sent to the CPU.
Rising, falling, or both edge sensing can be selected for the IRQAEC input pin with bits AIAGS1
and AIAGS0 in AEGSR.
15.4.4 Event Counter PWM Operation
When the ECPWME bit in AEGSR is 1, the ECH and ECL input clocks are enabled when event
counter PWM output (IECPWM) is high. When IECPWM is low, the input clocks are not input to
the counters, and so ECH and ECL do not count. ECH and ECL count operations can therefore be
controlled cyclically from outside by controlling event counter PWM. In this case, ECH and ECL
cannot be controlled individually.
IECPWM can also operate as an interrupt source.
Interrupt enabling is controlled by IENEC2 in IENR1. When an IECPWM interrupt is generated,
IRR1 interrupt request flag IRREC2 is set to 1. If IENEC2 in IENR1 is set to 1 at this time, an
interrupt request is sent to the CPU.
Rising, falling, or both edge detection can be selected for IECPWM interrupt sensing with bits
AIAGS1 and AIAGS0 in AEGSR.
Figure 15.4 and table 15.2 show examples of event counter PWM operation.
t
off
= T × (N
dr
+1)
t
on
t
cm
= T × (N
cm
+1)
t
on:
t
off:
t
cm:
T:
N
dr:
N
cm:
Clock input enable time
Clock input disable time
One conversion period
ECPWM input clock cycle
Value of ECPWDR
Fixed low when N
dr =H'FFFF
Value of ECPWCR
Figure 15.4 Event Counter Operation Waveform