ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 107

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

15.9.2
9223B–AVR–09/11
TCCR0B – Timer/Counter Control Register B
• Bit 7 – FOC0A: Force Output Compare A
The FOC0A bit is only active when the WGM bits specify a non-PWM mode.
However, for ensuring compatibility with future devices, this bit must be set to zero when
TCCR0B is written when operating in PWM mode. When writing a logical one to the FOC0A
bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC0A out-
put is changed according to its COM0A1:0 bits setting. Note that the FOC0A bit is
implemented as a strobe. Therefore it is the value present in the COM0A1:0 bits that deter-
mines the effect of the forced compare.
A FOC0A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using
OCR0A as TOP.
The FOC0A bit is always read as zero.
• Bit 6 – FOC0B: Force Output Compare B
The FOC0B bit is only active when the WGM bits specify a non-PWM mode.
However, for ensuring compatibility with future devices, this bit must be set to zero when
TCCR0B is written when operating in PWM mode. When writing a logical one to the FOC0B
bit, an immediate Compare Match is forced on the Waveform Generation unit. The OC0B out-
put is changed according to its COM0B1:0 bits setting. Note that the FOC0B bit is
implemented as a strobe. Therefore it is the value present in the COM0B1:0 bits that deter-
mines the effect of the forced compare.
A FOC0B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using
OCR0B as TOP.
The FOC0B bit is always read as zero.
• Bits 5:4 – Reserved
These bits are reserved bits in the Atmel
zero.
• Bit 3 – WGM02: Waveform Generation Mode
See the description in the
• Bits 2:0 – CS02:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter.
Bit
0x25 (0x45)
Read/Write
Initial Value
Atmel ATmega48PA/88PA/168PA [Preliminary]
FOC0A
W
7
0
FOC0B
W
“TCCR0A – Timer/Counter Control Register A” on page
6
0
R
5
–
0
®
ATmega48PA/88PA/168PA and will always read as
R
4
–
0
WGM02
R/W
3
0
CS02
R/W
2
0
CS01
R/W
1
0
CS00
R/W
0
0
104.
TCCR0B
107