ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 149

• 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

8011O–AVR–07/10
Figure 14-8. Timer/Counter Timing Diagram, no Prescaling
Figure 14-9 on page 149
Figure 14-9. Timer/Counter Timing Diagram, with Prescaler (f
Figure 14-10 on page 149
Figure 14-10. Timer/Counter Timing Diagram, Setting of OCF2A, with Prescaler (f
TCNTn
TCNTn
(clk
(clk
TOVn
TOVn
TCNTn
clk
clk
(clk
clk
clk
OCRnx
OCFnx
clk
clk
I/O
I/O
I/O
I/O
Tn
Tn
I/O
/1)
/8)
I/O
Tn
/8)
MAX - 1
OCRnx - 1
MAX - 1
shows the same timing data, but with the prescaler enabled.
shows the setting of OCF2A in all modes except CTC mode.
OCRnx
MAX
MAX
OCRnx Value
ATmega164P/324P/644P
OCRnx + 1
BOTTOM
BOTTOM
clk_I/O
/8)
BOTTOM + 1
BOTTOM + 1
OCRnx + 2
clk_I/O
/8)
149