Datasheet

48
ATmega169A/PA/329A/PA/649A/P/3290A/PA/6490A/P [DATASHEET]
8284E–AVR–02/2013
Figure 11-3. MCU start-up, RESET extended externally.
11.2.2 External Reset
An External Reset is generated by a low level on the RESET
pin. Reset pulses longer than the minimum pulse
width (see ”System and reset characteristics” on page 334) will generate a reset, even if the clock is not running.
Shorter pulses are not guaranteed to generate a reset. When the applied signal reaches the Reset Threshold Volt-
age – V
RST
– on its positive edge, the delay counter starts the MCU after the Time-out period – t
TOUT
– has expired.
Figure 11-4. External reset during operation.
RESET
TIME-OUT
INTERNAL
RESET
t
TOUT
V
POT
V
RST
V
CC
CC