Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet
Product codes
MEGA328P-XMINI
51
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
Figure 11-5.
Brown-out Reset During Operation
11.6
Watchdog System Reset
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On the falling edge
of this pulse, the delay timer starts counting the Time-out period t
of this pulse, the delay timer starts counting the Time-out period t
TOUT
. Refer to
for details on operation
of the Watchdog Timer.
Figure 11-6.
Watchdog System Reset During Operation
11.7
Internal Voltage Reference
ATmega48A/PA/88A/PA/168A/PA/328/P features an internal bandgap reference. This reference is used for
Brown-out Detection, and it can be used as an input to the Analog Comparator or the ADC.
Brown-out Detection, and it can be used as an input to the Analog Comparator or the ADC.
11.7.1 Voltage Reference Enable Signals and Start-up Time
The voltage reference has a start-up time that may influence the way it should be used. The start-up time is
given in
given in
. To save power, the reference is not always turned on.
The reference is on during the following situations:
1. When the BOD is enabled (by programming the BODLEVEL [2:0] Fuses).
2.
When the bandgap reference is connected to the Analog Comparator (by setting the ACBG bit in ACSR).
3.
When the ADC is enabled.
Thus, when the BOD is not enabled, after setting the ACBG bit or enabling the ADC, the user must always allow
the reference to start up before the output from the Analog Comparator or ADC is used. To reduce power
consumption in Power-down mode, the user can avoid the three conditions above to ensure that the reference
is turned off before entering Power-down mode.
the reference to start up before the output from the Analog Comparator or ADC is used. To reduce power
consumption in Power-down mode, the user can avoid the three conditions above to ensure that the reference
is turned off before entering Power-down mode.
V
CC
RESET
TIME-OUT
INTERNAL
RESET
V
BOT-
V
BOT+
t
TOUT
CK
CC