123
2588F–AVR–06/2013
ATtiny261/461/861
Note that, if 10-bit accuracy is used special procedures must be followed when accessing the
internal 10-bit Output Compare Registers via the 8-bit AVR data bus. These procedures are
12.12.13 TIMSK – Timer/Counter1 Interrupt Mask Register
Bit 7 – OCIE1D: Timer/Counter1 Output Compare Interrupt Enable
When the OCIE1D bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 Compare MatchD, interrupt is enabled. The corresponding interrupt at vector
$010 is executed if a compare matchD occurs. The Compare Flag in Timer/Counter1 is set (one)
in the Timer/Counter Interrupt Flag Register.
Bit 6 – OCIE1A: Timer/Counter1 Output Compare Interrupt Enable
When the OCIE1A bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 Compare MatchA, interrupt is enabled. The corresponding interrupt at vector
$003 is executed if a compare matchA occurs. The Compare Flag in Timer/Counter1 is set (one)
in the Timer/Counter Interrupt Flag Register.
Bit 5 – OCIE1B: Timer/Counter1 Output Compare Interrupt Enable
When the OCIE1B bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 Compare MatchB, interrupt is enabled. The corresponding interrupt at vector
$009 is executed if a compare matchB occurs. The Compare Flag in Timer/Counter1 is set (one)
in the Timer/Counter Interrupt Flag Register.
Bit 2 – TOIE1: Timer/Counter1 Overflow Interrupt Enable
When the TOIE1 bit is set (one) and the I-bit in the Status Register is set (one), the
Timer/Counter1 Overflow interrupt is enabled. The corresponding interrupt (at vector $004) is
executed if an overflow in Timer/Counter1 occurs. The Overflow Flag (Timer1) is set (one) in the
Timer/Counter Interrupt Flag Register - TIFR.
12.12.14 TIFR – Timer/Counter1 Interrupt Flag Register
Bit 7 – OCF1D: Output Compare Flag 1D
The OCF1D bit is set (one) when compare match occurs between Timer/Counter1 and the data
value in OCR1D - Output Compare Register 1D. OCF1D is cleared by hardware when executing
the corresponding interrupt handling vector. Alternatively, OCF1D is cleared, after synchroniza-
tion clock cycle, by writing a logic one to the flag. When the I-bit in SREG, OCIE1D, and OCF1D
are set (one), the Timer/Counter1 D compare match interrupt is executed.
Bit 6 – OCF1A: Output Compare Flag 1A
The OCF1A bit is set (one) when compare match occurs between Timer/Counter1 and the data
value in OCR1A - Output Compare Register 1A. OCF1A is cleared by hardware when executing
Bit
76543210
OCIE1D
OCIE1A
OCIE1B
OCIE0A
OCIE0B
TOIE1
TOIE0
TICIE0
TIMSK
Read/Write
R/W
Initial value
00000000
Bit
76543210
OCF1D
OCF1A
OCF1B
OCF0A
OCF0B
TOV1
TOV0
ICF0
TIFR
Read/Write
R/W
Initial value
00000000