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15.4
Interrupts
During interval timer mode operation, an overflow generates an interval timer interrupt (WOVI).
The interval timer interrupt is requested whenever the OVF flag is set to 1 in TCSR. OVF must be
cleared to 0 in the interrupt handling routine.
If an NMI request has been chosen in the watchdog timer mode, an NMI request is generated
when a TCNT overflow occurs.
15.5
Usage Notes
15.5.1
Contention between Timer Counter (TCNT) Write and Increment
If a timer counter clock pulse is generated during the T
takes priority and the timer counter is not incremented. Figure 15-8 shows this operation.
ø
Address
Internal write signal
TCNT input clock
TCNT
Figure 15-8 Contention between TCNT Write and Increment
580
state of a TCNT write cycle, the write
2
TCNT write cycle
T
T
1
2
N
M
Counter write data
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