ATmega325 Atmel Corporation, ATmega325 Datasheet - Page 44

• Manufacturer Part Number: ATmega325
• Manufacturer: Atmel Corporation

Specifications of ATmega325

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

11.6
11.7
11.7.1
2570N–AVR–05/11
Watchdog Reset
Internal Voltage Reference
Voltage Reference Enable Signals and Start-up Time
Figure 11-5. Brown-out Reset During Operation
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
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Figure 11-6. Watchdog Reset During Operation
Atmel ATmega325/3250/645/6450 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.
The voltage reference has a start-up time that may influence the way it should be used. The
start-up time is given in
reference is not always turned on. The reference is on during the following situations:
1. When the BOD is enabled (by programming the BODLEVEL [1..0] Fuse).
2. When the bandgap reference is connected to the Analog Comparator (by setting the
3. When the ADC is enabled.
ACBG bit in ACSR).
for details on operation of the Watchdog Timer.
CC
INTERNAL
TIME-OUT
RESET
RESET
V
CC
“System and Reset Characteristics” on page
V
CK
BOT-
ATmega325/3250/645/6450
V
t
TOUT
BOT+
301. To save power, the
TOUT
. Refer to
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