Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet
Product codes
MEGA328P-XMINI
133
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
shows the COM1x1:0 bit functionality when the WGM13:0 bits are set to the phase correct or the
phase and frequency correct, PWM mode.
Note:
1.
A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. See
• Bit 1:0 – WGM11:0: Waveform Generation Mode
Combined with the WGM13:2 bits found in the TCCR1B Register, these bits control the counting sequence of
the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used,
see
the counter, the source for maximum (TOP) counter value, and what type of waveform generation to be used,
see
. Modes of operation supported by the Timer/Counter unit are: Normal mode (counter), Clear
Timer on Compare match (CTC) mode, and three types of Pulse Width Modulation (PWM) modes. (See
).
Table 16-3.
Compare Output Mode, Phase Correct and Phase and Frequency Correct PWM
COM1A1/COM1B1
COM1A0/COM1B0
Description
0
0
Normal port operation, OC1A/OC1B disconnected.
0
1
WGM13:0 = 9 or 11: Toggle OC1A on Compare
Match, OC1B disconnected (normal port operation).
For all other WGM1 settings, normal port operation,
OC1A/OC1B disconnected.
Match, OC1B disconnected (normal port operation).
For all other WGM1 settings, normal port operation,
OC1A/OC1B disconnected.
1
0
Clear OC1A/OC1B on Compare Match when up-
counting. Set OC1A/OC1B on Compare Match when
downcounting.
counting. Set OC1A/OC1B on Compare Match when
downcounting.
1
1
Set OC1A/OC1B on Compare Match when up-
counting. Clear OC1A/OC1B on Compare Match
when downcounting.
counting. Clear OC1A/OC1B on Compare Match
when downcounting.
Table 16-4.
Waveform Generation Mode Bit Description
Mode
WGM13
WGM12
(CTC1)
WGM11
(PWM11)
WGM10
(PWM10)
Timer/Counter Mode of
Operation
Operation
TOP
Update of
OCR1
OCR1
x
at
TOV1 Flag
Set on
Set on
0
0
0
0
0
Normal
0xFFFF
Immediate
MAX
1
0
0
0
1
PWM, Phase Correct, 8-bit
0x00FF
TOP
BOTTOM
2
0
0
1
0
PWM, Phase Correct, 9-bit
0x01FF
TOP
BOTTOM
3
0
0
1
1
PWM, Phase Correct, 10-bit
0x03FF
TOP
BOTTOM
4
0
1
0
0
CTC
OCR1A
Immediate
MAX
5
0
1
0
1
Fast PWM, 8-bit
0x00FF
BOTTOM
TOP
6
0
1
1
0
Fast PWM, 9-bit
0x01FF
BOTTOM
TOP
7
0
1
1
1
Fast PWM, 10-bit
0x03FF
BOTTOM
TOP
8
1
0
0
0
PWM, Phase and Frequency
Correct
Correct
ICR1
BOTTOM
BOTTOM
9
1
0
0
1
PWM, Phase and Frequency
Correct
Correct
OCR1A
BOTTOM
BOTTOM
10
1
0
1
0
PWM, Phase Correct
ICR1
TOP
BOTTOM
11
1
0
1
1
PWM, Phase Correct
OCR1A
TOP
BOTTOM
12
1
1
0
0
CTC
ICR1
Immediate
MAX