ATMEGA325-16AJ ATMEL [ATMEL Corporation], ATMEGA325-16AJ Datasheet - Page 39

• Manufacturer Part Number: ATMEGA325-16AJ
• Description: 8-bit Microcontroller with In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Power-on Reset
2570A–AVR–09/04
Figure 15. Reset Logic
Table 16. Reset Characteristics
Notes:
A Power-on Reset (POR) pulse is generated by an On-chip detection circuit. The detec-
tion level is defined in Table 16. The POR is activated whenever V
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. Reach-
ing the Power-on Reset threshold voltage invokes the delay counter, which determines
how long the device is kept in RESET after V
again, without any delay, when V
Symbol
BODLEVEL [1..0]
V
V
t
RST
POT
RST
1. The Power-on Reset will not work unless the supply voltage has been below V
(falling)
Parameter
Power-on Reset Threshold
Voltage (rising)
Power-on Reset Threshold
Voltage (falling)
Minimum pulse width on
RESET Pin
RESET Pin Threshold Voltage
Pull-up Resistor
JTAG Reset
Register
FILTER
SPIKE
(1)
CKSEL[3:0]
Power-on Reset
Reset Circuit
SUT[1:0]
Brown-out
Watchdog
Oscillator
Generator
CC
Circuit
Clock
decreases below the detection level.
ATmega325/3250/645/6450
CK
Condition
T
T
V
V
A
A
to 85°C
to 85°C
Register (MCUSR)
CC
CC
= -40°C
= -40°C
MCU Status
CC
DATA BUS
= 3V
= 3V
rise. The RESET signal is activated
Delay Counters
0.2V
Min
0.7
0.6
CC
Typ
800
1.0
0.9
TIMEOUT
CC
0.85V
Max
is below the
1.4
1.3
CC
Units
ns
POT
V
V
V
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