ATMEGA325-16AJ ATMEL [ATMEL Corporation], ATMEGA325-16AJ Datasheet - Page 133

• Manufacturer Part Number: ATMEGA325-16AJ
• Description: 8-bit Microcontroller with In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Timer/Counter Timing
Diagrams
2570A–AVR–09/04
•
The following figures show the Timer/Counter in synchronous mode, and the timer clock
(clk
be replaced by the Timer/Counter Oscillator clock. The figures include information on
when Interrupt Flags are set. Figure 60 contains timing data for basic Timer/Counter
operation. The figure shows the count sequence close to the MAX value in all modes
other than phase correct PWM mode.
Figure 60. Timer/Counter Timing Diagram, no Prescaling
Figure 61 shows the same timing data, but with the prescaler enabled.
Figure 61. Timer/Counter Timing Diagram, with Prescaler (f
Figure 62 shows the setting of OCF2A in all modes except CTC mode.
TCNTn
T2
(clk
TCNTn
(clk
The timer starts counting from a value higher than the one in OCR2A, and for that
reason misses the Compare Match and hence the OCn change that would have
happened on the way up.
TOVn
TOVn
clk
clk
clk
clk
) is therefore shown as a clock enable signal. In asynchronous mode, clk
I/O
I/O
I/O
Tn
I/O
Tn
/1)
/8)
MAX - 1
MAX - 1
ATmega325/3250/645/6450
MAX
MAX
BOTTOM
BOTTOM
clk_I/O
/8)
BOTTOM + 1
BOTTOM + 1
I/O
should
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