ATA6612 Datasheet, PDF (177/364 Pages) ATMEL Corporation – Microcontroller with LIN Transceiver, 5V Regulator and Watchdog

ATA6612/ATA6613
6.15.8.2
Timer/Counter Control Register B – TCCR2B
Bit
7
6
5
FOC2A FOC2B
–
Read/Write
W
W
R
Initial Value
0
0
0
4
3
2
1
0
–
WGM22 CS22 CS21 CS20
R
R
R
R/W
R/W
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.
TCCR2B
However, for ensuring 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 COM2A1:0 bits setting. Note that the FOC2A bit is imple-
mented as a strobe. Therefore it is the value present in the COM2A1:0 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.
However, for ensuring 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 COM2B1:0 bits setting. Note that the FOC2B bit is imple-
mented as a strobe. Therefore it is the value present in the COM2B1:0 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.
• Bits 5:4 – Res: Reserved Bits
These bits are reserved bits in the ATA6612/ATA6613 and will always read as zero.
• Bit 3 – WGM22: Waveform Generation Mode
See the description in “Timer/Counter Control Register A – TCCR2A” on page 174.
• Bit 2:0 – CS22:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter (see
Table 6-65 on page 178).
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