ATMEGA16U2-16AU Atmel, ATMEGA16U2-16AU Datasheet - Page 102

• Manufacturer Part Number: ATMEGA16U2-16AU
• Description: 8-bit Microcontrollers - MCU 16K Flash
• Manufacturer: Atmel

Specifications of ATMEGA16U2-16AU

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: AVR
• Data Bus Width: 8 bit
• Program Memory Size: 16 KB
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Program Memory Type: Flash
• Factory Pack Quantity: 1250

15.9
15.9.1
7799D–AVR–11/10
Register Description
TCCR0A – Timer/Counter Control Register A
• Bits 7:6 – COM0A[1:0]: Compare Match Output A Mode
These bits control the Output Compare pin (OC0A) behavior. If one or both of the COM0A1:0
bits are set, the OC0A 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 OC0A pin
must be set in order to enable the output driver.
When OC0A is connected to the pin, the function of the COM0A[1:0] bits depends on the
WGM0[2:0] bit setting.
bits are set to a normal or CTC mode (non-PWM).
Table 15-2.
Table 15-3
PWM mode.
Table 15-3.
Note:
Bit
0x24 (0x44)
Read/Write
Initial Value
COM0A1
COM0A1
0
0
1
1
0
0
1
1
1. A special case occurs when OCR0A equals TOP and COM0A1 is set. In this case, the Com-
pare Match is ignored, but the set or clear is done at TOP. See
for more details.
shows the COM0A[1:0] bit functionality when the WGM0[1:0] bits are set to fast
COM0A1
Compare Output Mode, non-PWM Mode
Compare Output Mode, Fast PWM Mode
R/W
COM0A0
COM0A0
7
0
0
1
0
1
0
1
0
1
Table 15-2
COM0A0
R/W
6
0
Description
Normal port operation, OC0A disconnected.
Toggle OC0A on Compare Match
Clear OC0A on Compare Match
Set OC0A on Compare Match
Description
Normal port operation, OC0A disconnected.
WGM02 = 0: Normal Port Operation, OC0A Disconnected.
WGM02 = 1: Toggle OC0A on Compare Match.
Clear OC0A on Compare Match, set OC0A at TOP
Set OC0A on Compare Match, clear OC0A at TOP
COM0B1
shows the COM0A[1:0] bit functionality when the WGM0[2:0]
R/W
5
0
COM0B0
R/W
4
0
ATmega8U2/16U2/32U2
R
3
–
0
(1)
R
2
–
0
“Fast PWM Mode” on page 97
WGM01
R/W
1
0
WGM00
R/W
0
0
TCCR0A
102