ATA5771 ATMEL Corporation, ATA5771 Datasheet - Page 101

• Manufacturer Part Number: ATA5771
• Manufacturer: ATMEL Corporation

9.2.2
8006G–AVR–01/08
Pin Change Interrupt Timing
Note that if a level triggered interrupt is used for wake-up from Power-down, the required level
must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If
the level disappears before the end of the Start-up Time, the MCU will still wake up, but no inter-
rupt will be generated. The start-up time is defined by the SUT and CKSEL fuses, as described
in
If the low level on the interrupt pin is removed before the device has woken up then program
execution will not be diverted to the interrupt service routine but continue from the instruction fol-
lowing the SLEEP command.
An example of timing of a pin change interrupt is shown in
Figure 9-1.
pcint_setflag
pcint_in_(0)
“System Clock and Clock Options” on page
PCINT(0)
pcint_syn
pin_sync
pin_lat
PCINT(0)
PCIF
clk
clk
Timing of pin change interrupts
LE
pin_lat
D
Q
pin_sync
PCINT(0) in PCMSK(x)
pcint_in_(0)
23.
0
x
clk
Figure
pcint_syn
9-1.
ATtiny24/44/84
pcint_setflag
PCIF
49