ATMEGA48V_06 ATMEL [ATMEL Corporation], ATMEGA48V_06 Datasheet - Page 103

• Manufacturer Part Number: ATMEGA48V_06
• Description: 8-bit Microcontroller with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

2545J–AVR–12/06
Note:
Table 13-7
rect PWM mode.
Table 13-7.
Note:
• Bits 3, 2 – Res: Reserved Bits
These bits are reserved bits in the ATmega48/88/168 and will always read as zero.
• Bits 1:0 – WGM01:0: Waveform Generation Mode
Combined with the WGM02 bit found in the TCCR0B Register, these bits control the counting
sequence of the counter, the source for maximum (TOP) counter value, and what type of wave-
form generation to be used, see
unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and two types of
Pulse Width Modulation (PWM) modes (see
Table 13-8.
Notes:
Mode
COM0B1
0
1
2
3
4
5
6
7
0
0
1
1
1. A special case occurs when OCR0B equals TOP and COM0B1 is set. In this case, the Com-
1. A special case occurs when OCR0B equals TOP and COM0B1 is set. In this case, the Com-
2. BOTTOM = 0x00
1. MAX
WGM02
pare Match is ignored, but the set or clear is done at TOP. See
for more details.
pare Match is ignored, but the set or clear is done at TOP. See
page 97
shows the COM0B1:0 bit functionality when the WGM02:0 bits are set to phase cor-
0
0
0
0
1
1
1
1
Compare Output Mode, Phase Correct PWM Mode
Waveform Generation Mode Bit Description
COM0B0
for more details.
= 0xFF
0
1
0
1
WGM01
0
0
1
1
0
0
1
1
Description
Normal port operation, OC0B disconnected.
Reserved
Clear OC0B on Compare Match when up-counting. Set OC0B on
Compare Match when down-counting.
Set OC0B on Compare Match when up-counting. Clear OC0B on
Compare Match when down-counting.
Table
WGM00
0
1
0
1
0
1
0
1
13-8. Modes of operation supported by the Timer/Counter
Timer/Counter
Mode of
Operation
Normal
PWM, Phase
Correct
CTC
Fast PWM
Reserved
PWM, Phase
Correct
Reserved
Fast PWM
”Modes of Operation” on page
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
ATmega48/88/168
–
–
(1)
”Phase Correct PWM Mode” on
”Fast PWM Mode” on page 96
Update of
Immediate
Immediate
BOTTOM
BOTTOM
OCRx at
TOP
TOP
–
–
94).
Set on
TOV Flag
BOTTOM
BOTTOM
MAX
MAX
MAX
TOP
–
–
(1)(2)
103