atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 100

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

100
ATmega32U4
• Bits 7:6 – COM01A: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 COM0A1:0 bits depends on the
WGM02:0 bit setting.
are set to a normal or CTC mode (non-PWM).
Table 13-1.
Table 13-2
mode.
Table 13-2.
Note:
Table 13-3
rect PWM mode.
Table 13-3.
Initial Value
COM0A1
COM0A1
COM0A1
0
0
1
1
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 COM0A1:0 bit functionality when the WGM02:0 bits are set to phase cor-
shows the COM0A1:0 bit functionality when the WGM01:0 bits are set to fast PWM
0
Compare Output Mode, non-PWM Mode
Compare Output Mode, Fast PWM Mode
Compare Output Mode, Phase Correct PWM Mode
COM0A0
COM0A0
COM0A0
0
1
0
1
0
1
0
1
0
1
0
1
Table 13-1
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
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 when up-counting. Set OC0A on
Compare Match when down-counting.
Set OC0A on Compare Match when up-counting. Clear OC0A on
Compare Match when down-counting.
0
shows the COM0A1:0 bit functionality when the WGM02:0 bits
0
0
(1)
0
0
(1)
“Fast PWM Mode” on page 95
0
7766A–AVR–03/08