ATMEGA644A-PU Atmel, ATMEGA644A-PU Datasheet - Page 89

• Manufacturer Part Number: ATMEGA644A-PU
• Description: IC MCU AVR 64K FLASH 40PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644A-PU

• 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): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: JTAG, TWI, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

164A/164PA/324A/324PA/644A/644PA/1284/1284P
The alternate pin configuration is as follows:
• OC2A/PCINT31 – Port D, Bit 7
OC2A, Output Compare Match A output: The PD7 pin can serve as an external output for the
Timer/Counter2 Output Compare A. The pin has to be configured as an output (DDD7 set (one))
to serve this function. The OC2A pin is also the output pin for the PWM mode timer function.
PCINT31, Pin Change Interrupt Source 31:The PD7 pin can serve as an external interrupt
source.
• ICP1/OC2B/PCINT30 – Port D, Bit 6
ICP1, Input Capture Pin 1: The PD6 pin can act as an input capture pin for Timer/Counter1.
OC2B, Output Compare Match B output: The PD6 pin can serve as an external output for the
Timer/Counter2 Output Compare B. The pin has to be configured as an output (DDD6 set (one))
to serve this function. The OC2B pin is also the output pin for the PWM mode timer function.
PCINT30, Pin Change Interrupt Source 30: The PD6 pin can serve as an external interrupt
source.
• OC1A/PCINT29 – Port D, Bit 5
OC1A, Output Compare Match A output: The PD5 pin can serve as an external output for the
Timer/Counter1 Output Compare A. The pin has to be configured as an output (DDD5 set (one))
to serve this function. The OC1A pin is also the output pin for the PWM mode timer function.
PCINT29, Pin Change Interrupt Source 29: The PD5 pin can serve as an external interrupt
source.
• OC1B/XCK1/PCINT28 – Port D, Bit 4
OC1B, Output Compare Match B output: The PB4 pin can serve as an external output for the
Timer/Counter1 Output Compare B. The pin has to be configured as an output (DDD4 set (one))
to serve this function. The OC1B pin is also the output pin for the PWM mode timer function.
XCK1, USART1 External clock. The Data Direction Register (DDB4) controls whether the clock
is output (DDD4 set “one”) or input (DDD4 cleared). The XCK4 pin is active only when the
USART1 operates in Synchronous mode.
PCINT28, Pin Change Interrupt Source 28: The PD4 pin can serve as an external interrupt
source.
• INT1/TXD1/PCINT27 – Port D, Bit 3
INT1, External Interrupt source 1. The PD3 pin can serve as an external interrupt source to the
MCU.
TXD1, Transmit Data (Data output pin for the USART1). When the USART1 Transmitter is
enabled, this pin is configured as an output regardless of the value of DDD3.
PCINT27, Pin Change Interrupt Source 27: The PD3 pin can serve as an external interrupt
source.
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