ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 4

• Manufacturer Part Number: ATmega644P
• Manufacturer: Atmel Corporation

Specifications of ATmega644P

• Flash (kbytes): 64 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• 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): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

2. Overview
2.1
Figure 2-1.
4
RESET
XTAL1
XTAL2
Block Diagram
VCC
GND
ATmega164P/324P/644P
Block Diagram
POR / BOD &
Supervision
Generation
Watchdog
Watchdog
Oscillator
Oscillator
Circuits /
RESET
Power
Timer
Clock
TOSC2/PC7
The ATmega164P/324P/644P is a low-power CMOS 8-bit microcontroller based on the AVR
enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the
ATmega164P/324P/644P achieves throughputs approaching 1 MIPS per MHz allowing the sys-
tem designer to optimize power consumption versus processing speed.
The AVR core combines a rich instruction set with 32 general purpose working registers. All the
32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent
registers to be accessed in one single instruction executed in one clock cycle. The resulting
architecture is more code efficient while achieving throughputs up to ten times faster than con-
ventional CISC microcontrollers.
TOSC1/PC6
JTAG/OCD
PORT C (8)
EEPROM
TWI
Converter
PC5..0
A/D
PORT A (8)
PA7..0
FLASH
Bandgap reference
Internal
CPU
SRAM
Comparator
Analog
PORT B (8)
8 bit T/C 0
PORT D (8)
16 bit T/C 1
8 bit T/C 2
PB7..0
PD7..0
SPI
USART 0
USART 1
8011OS–AVR–07/10