7 tifr - timer/counter0 interrupt flag register – Rainbow Electronics ATtiny861_V User Manual
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87
2588B–AVR–11/06
ATtiny261/461/861
14.10.7
TIFR – Timer/Counter0 Interrupt Flag Register
• Bit 4– OCF0A: Output Compare Flag 0 A
The OCF0A bit is set when a Compare Match occurs between the Timer/Counter0 and the data
in OCR0A – Output Compare Register0. OCF0A is cleared by hardware when executing the cor-
responding interrupt handling vector. Alternatively, OCF0A is cleared by writing a logic one to
the flag. When the I-bit in SREG, OCIE0A (Timer/Counter0 Compare Match Interrupt Enable),
and OCF0A are set, the Timer/Counter0 Compare Match Interrupt is executed.
The OCF0A is also set in 16-bit mode when a Compare Match occurs between the
Timer/Counter and 16-bit data in OCR0B/A. The OCF0A is not set in Input Capture mode when
the Output Compare Register OCR0A is used as an Input Capture Register.
• Bit 3 – OCF0B: Output Compare Flag 0 B
The OCF0B bit is set when a Compare Match occurs between the Timer/Counter and the data in
OCR0B – Output Compare Register0 B. OCF0B is cleared by hardware when executing the cor-
responding interrupt handling vector. Alternatively, OCF0B is cleared by writing a logic one to
the flag. When the I-bit in SREG, OCIE0B (Timer/Counter Compare B Match Interrupt Enable),
and OCF0B are set, the Timer/Counter Compare Match Interrupt is executed.
The OCF0B is not set in 16-bit Output Compare mode when the Output Compare Register
OCR0B is used as the high byte of the 16-bit Output Compare Register or in 16-bit Input Cap-
ture mode when the Output Compare Register OCR0B is used as the high byte of the Input
Capture Register.
• Bit 1 – TOV0: Timer/Counter0 Overflow Flag
The bit TOV0 is set when an overflow occurs in Timer/Counter0. TOV0 is cleared by hardware
when executing the corresponding interrupt handling vector. Alternatively, TOV0 is cleared by
writing a logic one to the flag. When the SREG I-bit, TOIE0 (Timer/Counter0 Overflow Interrupt
Enable), and TOV0 are set, the Timer/Counter0 Overflow interrupt is executed.
• Bits 0 – ICF0: Timer/Counter0, Input Capture Flag
This flag is set when a capture event occurs on the ICP0 pin. When the Input Capture Register
(ICR0) is set to be used as the TOP value, the ICF0 flag is set when the counter reaches the
TOP value.
ICF0 is automatically cleared when the Input Capture Interrupt Vector is executed. Alternatively,
ICF0 can be cleared by writing a logic one to its bit location.
Bit
7
6
5
4
3
2
1
0
0x38 (0x58)
OCF1D
OCF1A
OCF1B
OCF0A
OCF0B
TOV1
TOV0
ICF0
TIFR
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
Initial Value
0
0
0
0
0
0
0
0