Datasheet

15.9.2. TC0 Control Register B
When addressing I/O Registers as data space using LD and ST instructions, the provided offset must be
used. When using the I/O specific commands IN and OUT, the offset is reduced by 0x20, resulting in an
I/O address offset within 0x00 - 0x3F.
Name: TCCR0B
Offset: 0x45
Reset: 0x00
Property: When addressing as I/O Register: address offset is 0x25
Bit 7 6 5 4 3 2 1 0
FOC0A FOC0B WGM02 CS0[2:0]
Access
R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0
Bit 7 – FOC0A: Force Output Compare A
The FOC0A bit is only active when the WGM bits specify a non-PWM mode.
To ensure 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 output is changed according to its COM0A[1:0] bits
setting. The FOC0A bit is implemented as a strobe. Therefore it is the value present in the COM0A[1:0]
bits that determines 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.
To ensure 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 output is changed according to its COM0B[1:0] bits
setting. The FOC0B bit is implemented as a strobe. Therefore it is the value present in the COM0B[1:0]
bits that determines 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.
Bit 3 – WGM02: Waveform Generation Mode
Refer to TCCR0A.
Bits 2:0 – CS0[2:0]: Clock Select 0 [n = 0..2]
The three Clock Select bits select the clock source to be used by the Timer/Counter.
Atmel ATmega16M1/32M1/64M1 [DATASHEET]
Atmel-8209F-ATmega16M1/32M1/64M1_Datasheet_Complete-10/2016
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