ATMEGA644V-10MUR Atmel, ATMEGA644V-10MUR Datasheet - Page 146

• Manufacturer Part Number: ATMEGA644V-10MUR
• Description: MCU AVR 64K FLASH 10MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644V-10MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.11 Register Description
15.11.1
146
ATmega644
TCCR2A – Timer/Counter Control Register A
• Bits 7:6 – COM2A1:0: Compare Match Output A Mode
These bits control the Output Compare pin (OC2A) behavior. If one or both of the COM2A1:0
bits are set, the OC2A 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 OC2A pin
must be set in order to enable the output driver.
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:
Bit
(0xB0)
Read/Write
Initial Value
COM2A1
COM2A1
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-
pare Match is ignored, but the set or clear is done at BOTTOM. See
page 138
shows the COM2A1:0 bit functionality when the WGM21:0 bits are set to fast PWM
COM2A1
Compare Output Mode, non-PWM Mode
Compare Output Mode, Fast PWM Mode
R/W
7
0
COM2A0
COM2A0
for more details.
0
1
0
1
0
1
0
1
Table 15-2
COM2A0
R/W
6
0
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)
COM2B1
shows the COM2A1:0 bit functionality when the WGM22:0 bits
R/W
5
0
COM2B0
R/W
4
0
R
3
–
0
(1)
R
2
0
–
WGM21
R/W
1
0
”Fast PWM Mode” on
WGM20
R/W
0
0
2593N–AVR–07/10
TCCR2A