Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet

Product codes
MEGA328P-XMINI
Page of 657
49
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
Figure 11-1.
Reset Logic
11.3
Power-on Reset
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detection level is defined in 
. The POR is activated whenever V
CC
 is below the detection 
level. The POR circuit can be used to trigger the start-up Reset, as well as to detect a failure in supply voltage.
A Power-on Reset (POR) circuit ensures that the device is reset from Power-on. Reaching the Power-on Reset 
threshold voltage invokes the delay counter, which determines how long the device is kept in RESET after V
CC
 
rise. The RESET signal is activated again, without any delay, when V
CC
 decreases below the detection level.
Figure 11-2.
MCU Start-up, RESET Tied to V
CC
MCU Status
Register (MCUSR)
Brown-out
Reset Circuit
BODLEVEL [2..0]
Delay Counters
CKSEL[3:0]
CK
TIMEOUT
WDRF
BORF
EXTRF
PORF
DATA BUS
Clock
Generator
SPIKE
FILTER
Pull-up Resistor
Watchdog
Oscillator
SUT[1:0]
Power-on Reset
Circuit
RSTDISBL
V
RESET
TIME-OUT
INTERNAL
RESET
t
TOUT
V
POT
V
RST
CC