ATmega329P Atmel Corporation, ATmega329P Datasheet - Page 104

• Manufacturer Part Number: ATmega329P
• Manufacturer: Atmel Corporation

Specifications of ATmega329P

• Flash (kbytes): 32 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 54
• Ext Interrupts: 17
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Segment Lcd: 100
• 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): 2
• Eeprom (bytes): 1024
• 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: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

14.8
8021G–AVR–03/11
Timer/Counter Timing Diagrams
• The timer starts counting from a value higher than the one in OCR0A, and for that reason
The Timer/Counter is a synchronous design and the timer clock (clk
clock enable signal in the following figures. The figures include information on when Interrupt
Flags are set.
the count sequence close to the MAX value in all modes other than phase correct PWM mode.
Figure 1. Timer/Counter Timing Diagram, no Prescaling
Figure 2
Figure 2. Timer/Counter Timing Diagram, with Prescaler (f
Figure 3
Figure 3. Timer/Counter Timing Diagram, Setting of OCF0A, with Prescaler (f
symmetry around BOTTOM the OCn value at MAX must correspond to the result of an up-
counting Compare Match.
misses the Compare Match and hence the OCn change that would have happened on the way
up.
TCNTn
TCNTn
TCNTn
(clk
(clk
(clk
OCRnx
OCFnx
TOVn
TOVn
clk
clk
clk
clk
clk
clk
I/O
I/O
I/O
I/O
I/O
I/O
Tn
Tn
Tn
/1)
/8)
/8)
shows the same timing data, but with the prescaler enabled.
shows the setting of OCF0A in all modes except CTC mode.
Figure 1
contains timing data for basic Timer/Counter operation. The figure shows
OCRnx - 1
MAX - 1
MAX - 1
OCRnx
MAX
MAX
OCRnx Value
ATmega329P/3290P
clk_I/O
OCRnx + 1
BOTTOM
BOTTOM
/8)
T0
) is therefore shown as a
clk_I/O
BOTTOM + 1
BOTTOM + 1
OCRnx + 2
/8)
104