ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 149

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

Modes of Operation
Table 82. Waveform Generation Mode Bit Description
Note:
2549K–AVR–01/07
Mode
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
1. The CTCn and PWMn1:0 bit definition names are obsolete. Use the
WGMn3
location of these bits are compatible with previous versions of the timer.
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
WGMn2
(CTCn)
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
(PWMn1)
WGMn1
A change of the COMnx1:0 bits state will have effect at the first compare match after the
bits are written. For non-PWM modes, the action can be forced to have immediate effect
by using the FOCnx strobe bits.
The mode of operation, i.e., the behavior of the Timer/Counter and the Output Compare
pins, is defined by the combination of the Waveform Generation mode (WGMn3:0) and
Compare Output mode (COMnx1:0) bits. The Compare Output mode bits do not affect
the counting sequence, while the Waveform Generation mode bits do. The COMnx1:0
bits control whether the PWM output generated should be inverted or not (inverted or
non-inverted PWM). For non-PWM modes the COMnx1:0 bits control whether the out-
put should be set, cleared or toggle at a compare match (See “Compare Match Output
Unit” on page 148.)
For detailed timing information refer to “Timer/Counter Timing Diagrams” on page 157.
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
(PWMn0)
WGMn0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
(1)
Timer/Counter
Mode of Operation
Normal
PWM, Phase Correct, 8-bit
PWM, Phase Correct, 9-bit
PWM, Phase Correct, 10-bit
CTC
Fast PWM, 8-bit
Fast PWM, 9-bit
Fast PWM, 10-bit
PWM, Phase and Frequency
Correct
PWM,Phase and Frequency
Correct
PWM, Phase Correct
PWM, Phase Correct
CTC
(Reserved)
Fast PWM
Fast PWM
ATmega640/1280/1281/2560/2561
WGM
n2:0 definitions. However, the functionality and
TOP
0xFFFF
0x00FF
0x01FF
0x03FF
OCRnA
0x00FF
0x01FF
0x03FF
ICRn
OCRnA
ICRn
OCRnA
ICRn
–
ICRn
OCRnA
Update of
OCRn
Immediate
TOP
TOP
TOP
Immediate
BOTTOM
BOTTOM
BOTTOM
BOTTOM
BOTTOM
TOP
TOP
Immediate
–
BOTTOM
BOTTOM
x
at
TOVn Flag
Set on
MAX
BOTTOM
BOTTOM
BOTTOM
MAX
TOP
TOP
TOP
BOTTOM
BOTTOM
BOTTOM
BOTTOM
MAX
–
TOP
TOP
149