Datasheet

80
2586D–AVR–02/06
ATtiny25/45/85
13.8.6 TIMSK – Timer/Counter Interrupt Mask Register
• Bits 7:5, 0 – Res: Reserved Bits
These bits are reserved bits and will always read as zero.
• Bit 4 – OCIE0A: Timer/Counter0 Output Compare Match A Interrupt Enable
When the OCIE0A bit is written to one, and the I-bit in the Status Register is set, the
Timer/Counter0 Compare Match A interrupt is enabled. The corresponding interrupt is executed
if a Compare Match in Timer/Counter0 occurs, i.e., when the OCF0A bit is set in the
Timer/Counter 0 Interrupt Flag Register – TIFR0.
• Bit 3 – OCIE0B: Timer/Counter Output Compare Match B Interrupt Enable
When the OCIE0B bit is written to one, and the I-bit in the Status Register is set, the
Timer/Counter Compare Match B interrupt is enabled. The corresponding interrupt is executed if
a Compare Match in Timer/Counter occurs, i.e., when the OCF0B bit is set in the Timer/Counter
Interrupt Flag Register – TIFR0.
• Bit 1 – TOIE0: Timer/Counter0 Overflow Interrupt Enable
When the TOIE0 bit is written to one, and the I-bit in the Status Register is set, the
Timer/Counter0 Overflow interrupt is enabled. The corresponding interrupt is executed if an
overflow in Timer/Counter0 occurs, i.e., when the TOV0 bit is set in the Timer/Counter 0 Inter-
rupt Flag Register – TIFR0.
13.8.7 TIFR – Timer/Counter Interrupt Flag Register
• Bits 7, 0 – Res: Reserved Bits
These bits are reserved bits and will always read as zero.
• 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.
• 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.
Bit 76543210
0x39 –
OCIE1A OCIE1B OCIE0A OCIE0B TOIE1 TOIE0 – TIMSK
Read/Write R R R R R/W R/W R/W R
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
0x38 –
OCF1A OCF1B OCF0A OCF0B TOV1 TOV0 –TIFR
Read/Write RRRRR/WR/WR/WR
Initial Value00000000