ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 176

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

8-bit Timer/Counter2 with PWM and Asynchronous Operation
Overview
176
ATmega640/1280/1281/2560/2561
Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. The
main features are:
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A simplified block diagram of the 8-bit Timer/Counter is shown in Figure 59.. For the
actual placement of I/O pins, see “Pin Configurations” on page 2. CPU accessible I/O
Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O
Register and bit locations are listed in the “Register Description” on page 191.
The Power Reduction Timer/Counter2 bit, PRTIM2, in “PRR0 – Power Reduction Regis-
ter 0” on page 55 must be written to zero to enable Timer/Counter2 module.
Figure 66. 8-bit Timer/Counter Block Diagram
Single Channel Counter
Clear Timer on Compare Match (Auto Reload)
Glitch-free, Phase Correct Pulse Width Modulator (PWM)
Frequency Generator
10-bit Clock Prescaler
Overflow and Compare Match Interrupt Sources (TOV2, OCF2A and OCF2B)
Allows Clocking from External 32 kHz Watch Crystal Independent of the I/O Clock
Status flags
Timer/Counter
TCCRnA
OCRnA
TCNTn
OCRnB
=
=
Direction
Count
Clear
ASSRn
Synchronized Status flags
Control Logic
TOP
=
TCCRnB
asynchronous mode
Value
BOTTOM
Fixed
TOP
select (ASn)
clk
=
Tn
0
Prescaler
Synchronization Unit
OCnA
(Int.Req.)
OCnB
(Int.Req.)
Generation
Generation
Waveform
Waveform
TOVn
(Int.Req.)
OCnA
OCnB
Oscillator
T/C
clk
I/O
clk
clk
I/O
ASY
2549K–AVR–01/07
TOSC1
TOSC2