ATMEGA644PV ATMEL [ATMEL Corporation], ATMEGA644PV Datasheet - Page 152

• Manufacturer Part Number: ATMEGA644PV
• Description: 8-bit Microcontroller with 16/32/64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

152
ATmega164P/324P/644P
When OC2A is connected to the pin, the function of the COM2A1:0 bits depends on the
WGM22:0 bit setting.
are set to a normal or CTC mode (non-PWM).
Table 15-2.
Table 15-3
mode.
Table 15-3.
Note:
Table 15-4
rect PWM mode.
Table 15-4.
Note:
• Bits 5:4 – COM2B1:0: Compare Match Output B Mode
These bits control the Output Compare pin (OC2B) behavior. If one or both of the COM2B1:0
bits are set, the OC2B output overrides the normal port functionality of the I/O pin it is connected
to. However, note that the Data Direction Register (DDR) bit corresponding to the OC2B pin
must be set in order to enable the output driver.
COM2A1
COM2A1
COM2A1
0
0
1
1
0
0
1
1
0
0
1
1
1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Com-
1. A special case occurs when OCR2A equals TOP and COM2A1 is set. In this case, the Com-
pare Match is ignored, but the set or clear is done at BOTTOM. See
page 144
pare Match is ignored, but the set or clear is done at TOP. See
page 146
shows the COM2A1:0 bit functionality when the WGM22:0 bits are set to phase cor-
shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to fast PWM
Compare Output Mode, non-PWM Mode
Compare Output Mode, Fast PWM Mode
Compare Output Mode, Phase Correct PWM Mode
COM2A0
COM2A0
COM2A0
for more details.
for more details.
0
1
0
1
0
1
0
1
0
1
0
1
Table 15-2
Description
Normal port operation, OC0A disconnected.
Toggle OC2A on Compare Match
Clear OC2A on Compare Match
Set OC2A on Compare Match
Description
Normal port operation, OC2A disconnected.
WGM22 = 0: Normal Port Operation, OC0A Disconnected.
WGM22 = 1: Toggle OC2A on Compare Match.
Clear OC2A on Compare Match, set OC2A at BOTTOM,
(non-inverting mode).
Set OC2A on Compare Match, clear OC2A at BOTTOM,
(inverting mode).
Description
Normal port operation, OC2A disconnected.
WGM22 = 0: Normal Port Operation, OC2A Disconnected.
WGM22 = 1: Toggle OC2A on Compare Match.
Clear OC2A on Compare Match when up-counting. Set OC2A on
Compare Match when down-counting.
Set OC2A on Compare Match when up-counting. Clear OC2A on
Compare Match when down-counting.
shows the COM2A1:0 bit functionality when the WGM22:0 bits
(1)
(1)
”Phase Correct PWM Mode” on
”Fast PWM Mode” on
8011D–AVR–02/07