Datasheet
22.11.2 TC2 Control Register B
Name: TCCR2B
Offset: 0xB1
Reset: 0x00
Property: -
Bit 7 6 5 4 3 2 1 0
FOC2A FOC2B WGM22 CS2[2:0]
Access
R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0
Bit 7 – FOC2A Force Output Compare A
The FOC2A 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 TCCR2B is written when
operating in PWM mode. When writing a logical one to the FOC2A bit, an immediate compare match is
forced on the waveform generation unit. The OC2A output is changed according to its COM2A[1:0] bits
setting. Note that the FOC2A bit is implemented as a strobe. Therefore it is the value present in the
COM2A[1:0] bits that determines the effect of the forced compare.
A FOC2A strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2A as
TOP.
The FOC2A bit is always read as zero.
Bit 6 – FOC2B Force Output Compare B
The FOC2B 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 TCCR2B is written when
operating in PWM mode. When writing a logical one to the FOC2B bit, an immediate compare match is
forced on the waveform generation unit. The OC2B output is changed according to its COM2B[1:0] bits
setting. Note that the FOC2B bit is implemented as a strobe. Therefore it is the value present in the
COM2B[1:0] bits that determines the effect of the forced compare.
A FOC2B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using OCR2B as
TOP.
The FOC2B bit is always read as zero.
Bit 3 – WGM22 Waveform Generation Mode
Refer to 22.11.1 TCCR2A.
Bits 2:0 – CS2[2:0] Clock Select 2 [n = 0..2]
The three Clock Select bits select the clock source to be used by the timer/counter.
Table 22-10. Clock Select Bit Description
CS22 CS21 CS20 Description
0 0 0 No clock source (Timer/counter stopped).
0 0 1 clk
I/O
/1 (No prescaling)
ATmega48PA/88PA/168PA
8-bit Timer/Counter2 (TC2) with PWM and A...
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40002011A-page 217