Datasheet

114
8197C–AVR–05/11
ATtiny261A/461A/861A
COM1B1S and COM1B0S in TCCR1C will show here. See “TCCR1C – Timer/Counter1 Control
Register C” on page 116.
• Bit 3 – FOC1A: Force Output Compare Match 1A
The FOC1A bit is only active when the PWM1A bit specify a non-PWM mode.
Writing a logical one to this bit forces a change in the Waveform Output (OCW1A) and the Out-
put Compare pin (OC1A) according to the values already set in COM1A1 and COM1A0. If
COM1A1 and COM1A0 written in the same cycle as FOC1A, the new settings will be used. The
Force Output Compare bit can be used to change the output pin value regardless of the timer
value. The automatic action programmed in COM1A1 and COM1A0 takes place as if a compare
match had occurred, but no interrupt is generated.
The FOC1A bit always reads zero.
• Bit 2 – FOC1B: Force Output Compare Match 1B
The FOC1B bit is only active when the PWM1B bit specify a non-PWM mode.
Writing a logical one to this bit forces a change in the Waveform Output (OCW1B) and the Out-
put Compare pin (OC1B) according to the values already set in COM1B1 and COM1B0. If
COM1B1 and COM1B0 written in the same cycle as FOC1B, the new settings will be used. The
Force Output Compare bit can be used to change the output pin value regardless of the timer
value. The automatic action programmed in COM1B1 and COM1B0 takes place as if a compare
match had occurred, but no interrupt is generated.
The FOC1B bit always reads zero.
• Bit 1 – PWM1A: Pulse Width Modulator A Enable
When set (one) this bit enables PWM mode based on comparator OCR1A
• Bit 0 – PWM1B: Pulse Width Modulator B Enable
When set (one) this bit enables PWM mode based on comparator OCR1B.
12.12.2 TCCR1B – Timer/Counter1 Control Register B
• Bit 7 – PWM1X: PWM Inversion Mode
When this bit is set (one), the PWM Inversion Mode is selected and the Dead Time Generator
outputs, OC1x and OC1x
are inverted.
• Bit 6 – PSR1: Prescaler Reset Timer/Counter1
When this bit is set (one), the Timer/Counter1 prescaler (TCNT1 is unaffected) will be reset. The
bit will be cleared by hardware after the operation is performed. Writing a zero to this bit will have
no effect. This bit will always read as zero.
• Bits 5:4 – DTPS1[1:0]: Dead Time Prescaler Bits
The Timer/Counter1 Control Register B is a 8-bit read/write register.
Bit 76543210
0x2F (0x4F) PWM1X PSR1 DTPS11 DTPS10 CS13 CS12 CS11 CS10 TCCR1B
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial value00000000