Asynchronous Event Counter Operation Modes - Renesas H8/38024 Hardware Manual

Figure 9.23 shows an example of the operation of this function.
Input event
IRQAEC or
IECPWM
Actually counted
clock source
Counter value
N
9.7.4

Asynchronous Event Counter Operation Modes

Asynchronous event counter operation modes are shown in table 9.21.
Table 9.21 Asynchronous Event Counter Operation Modes
Operation
Mode Reset Active
Functions Functions Retained *
AEGSR Reset
Functions Functions Retained *
ECCR Reset
Functions Functions Retained *
ECCSR Reset
Functions Functions Functions *
ECH Reset
Functions Functions Functions *
ECL Reset
Functions Functions Retained *
IRQAEC Reset
Event Reset Functions Functions Retained
counter
PWM
Notes: 1. When an asynchronous external event is input, the counter increments but the counter
overflow H/L flags are not affected.
2. Operates when asynchronous external events are selected; halted and retained
otherwise.
3. Clock control by IRQAEC operates, but interrupts do not.
4. As the clock is stopped in module standby mode, IRQAEC has no effect.
N+1
Clock stopped
Figure 9.23 Example of Clock Control Operation
Sleep Watch
Edge generated by clock return
N+2 N+3
Subactive Subsleep
1
Functions Functions
1
Functions Functions
1
Functions Functions
1 * 2 Functions * 2 Functions *
1 * 2 Functions * 2 Functions *
3
Functions Functions
Retained Retained
Rev. 6.00, 08/04, page 317 of 628
N+4 N+5 N+6
Module
Standby Standby
Retained * 1
Retained
Retained * 1
Retained
Retained * 1
Retained
2 Functions * 1 * 2
Halted
2 Functions * 1 * 2
Halted
Retained * 3 Retained *
Retained Retained
4