ATMEGA8L ATMEL [ATMEL Corporation], ATMEGA8L Datasheet - Page 113

• Manufacturer Part Number: ATMEGA8L
• Description: 8-bit AVR with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Timer/Counter Timing
Diagrams
2486M–AVR–12/03
•
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 52 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 52. Timer/Counter Timing Diagram, no Prescaling
Figure 53 shows the same timing data, but with the prescaler enabled.
Figure 53. Timer/Counter Timing Diagram, with Prescaler (f
Figure 54 shows the setting of OCF2 in all modes except CTC mode.
TCNTn
TCNTn
(clk
(clk
TOVn
TOVn
clk
clk
clk
clk
T2
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.
I/O
I/O
I/O
) is therefore shown as a clock enable signal. In Asynchronous mode, clk
Tn
I/O
Tn
/1)
/8)
MAX - 1
MAX - 1
MAX
MAX
BOTTOM
BOTTOM
clk_I/O
ATmega8(L)
/8)
BOTTOM + 1
BOTTOM + 1
I/O
should
113