ATmega644P Atmel Corporation, ATmega644P Datasheet - Page 330

• 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

25.3
Table 25-4.
Notes:
25.3.1
25.3.2
Table 25-5.
8011O–AVR–07/10
Factory
Calibration
User
Calibration
Symbol
1/t
t
t
t
t
t
Δ
CLCL
CHCX
CLCX
CLCH
CHCL
t
CLCL
CLCL
Clock Characteristics
1. Voltage range for ATmega164PV/324PV/644PV.
2. Voltage range for ATmega164P/324P/644P.
External Clock Drive Waveforms
External Clock Drive
Calibration Accuracy of Internal RC Oscillator
External Clock Drive
Parameter
Oscillator Frequency
Clock Period
High Time
Low Time
Rise Time
Fall Time
Change in period from
one clock cycle to the
next
Figure 25-3. External Clock Drive Waveforms
7.3 MHz - 8.1 MHz
Frequency
8.0 MHz
V
V
Min.
IL1
250
100
100
CC
0
V
IH1
= 1.8V - 5.5V
1.8V - 5.5V
2.7V - 5.5V
Max.
2.0
2.0
4
2
V
3V
CC
(1)
(2)
Min.
V
100
40
40
0
CC
= 2.7V - 5.5V
ATmega164P/324P/644P
Max.
Temperature
-40°C - 85°C
1.6
1.6
10
2
25°C
V
Min.
50
20
20
CC
0
= 4.5V - 5.5V
Calibration Accuracy
Max.
0.5
0.5
20
2
±10%
±1%
Units
MHz
ns
μs
%
330