ATMEGA644P-20AUR Atmel, ATMEGA644P-20AUR Datasheet - Page 7

• Manufacturer Part Number: ATMEGA644P-20AUR
• Description: MCU AVR 64K FLASH 20MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-20AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.3.7
2.3.8
2.3.9
2.3.10
2.3.11
8011OS–AVR–07/10
RESET
XTAL1
XTAL2
AVCC
AREF
Reset input. A low level on this pin for longer than the minimum pulse length will generate a
reset, even if the clock is not running. The minimum pulse length is given in
Characteristics” on page
Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting Oscillator amplifier.
AVCC is the supply voltage pin for Port A and the Analog-to-digital Converter. It should be exter-
nally connected to V
to V
This is the analog reference pin for the Analog-to-digital Converter.
CC
through a low-pass filter.
CC
, even if the ADC is not used. If the ADC is used, it should be connected
332. Shorter pulses are not guaranteed to generate a reset.
ATmega164P/324P/644P
”System and Reset
7