ATmega644 Atmel Corporation, ATmega644 Datasheet - Page 344

• Manufacturer Part Number: ATmega644
• Manufacturer: Atmel Corporation

Specifications of ATmega644

• 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: 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): 4
• Eeprom (bytes): 2048
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

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ATmega644
Figure 27-34. I/O Pin Input Threshold Voltage vs. V
Figure 27-35. I/O Pin Input Hysteresis vs. V
2.5
1.5
0.5
0.6
0.5
0.4
0.3
0.2
0.1
2
1
0
0
1.5
1.5
2
2
2.5
2.5
3
3
IL
CC
V
V
CC
CC
3.5
3.5
(V)
(V)
CC
(V
4
4
IL
, IO Pin Read as “0“)
4.5
4.5
CC
5
5
5.5
5.5
-40°C
-40°C
2593N–AVR–07/10
85°C
25°C
25°C
85°C