atmega32c1 ATMEL Corporation, atmega32c1 Datasheet - Page 102

• Manufacturer Part Number: atmega32c1
• Description: Atmega32m1 Automotive 8-bit Avr Microcontroller With 32k/64k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

12.8.2
102
ATmega32/64/M1/C1
Timer/Counter Control Register B – TCCR0B
Table 12-7
rect PWM mode.
Table 12-7.
Note:
• Bits 3, 2 – Res: Reserved Bits
These bits are reserved bits in the ATmega32/64/M1/C1 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 12-8.
Notes:
Bit
Read/Write
Initial Value
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. MAX
2. BOTTOM = 0x00
WGM02
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
FOC0A
W
7
0
0
1
0
1
for more details.
WGM01
= 0xFF
0
0
1
1
0
0
1
1
FOC0B
W
6
0
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.
WGM00
Table
0
1
0
1
0
1
0
1
R
5
0
–
12-8. Modes of operation supported by the Timer/Counter
Timer/Count
er Mode of
Operation
Normal
PWM, Phase
Correct
CTC
Fast PWM
Reserved
PWM, Phase
Correct
Reserved
Fast PWM
“Modes of Operation” on page
R
4
–
0
WGM02
R
3
0
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
–
–
CS02
R
2
0
Immediate
Immediate
Update of
OCRx at
(1)
TOP
TOP
TOP
TOP
“Phase Correct PWM Mode” on
–
–
CS01
R/W
1
0
94).
Set on
TOV Flag
BOTTOM
BOTTOM
CS00
MAX
MAX
MAX
TOP
R/W
0
0
–
–
7647A–AVR–02/08
(1)(2)
TCCR0B