ATMEGA329P-20MN Atmel, ATMEGA329P-20MN Datasheet - Page 104

• Manufacturer Part Number: ATMEGA329P-20MN
• Description: IC MCU AVR 32K 20MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA329P-20MN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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