Datasheet
119
7701F–AVR–10/12
Atmel ATtiny24/44/84 [Preliminary]
14.11.9 TIFR1 – Timer/Counter Interrupt Flag Register 1
• Bit 7,6,4,3 – Reserved Bit
This bit is reserved for future use. For ensuring compatibility with future devices, this bit must
be written to logical zero when the register is written.
• Bit 5– ICF1: Timer/Counter1, Input Capture Flag
This flag is set when a capture event occurs on the ICP1 pin. When the input capture register
(ICR1) is set by the WGM13:0 to be used as the top value, the ICF1 flag is set when the coun-
ter reaches the top value.
ICF1 is automatically cleared when the input capture interrupt vector is executed. Alterna-
tively, ICF1 can be cleared by writing a logical one to its bit location.
• Bit 2– OCF1B: Timer/Counter1, Output Compare B Match Flag
This flag is set in the timer clock cycle after the counter (TCNT1) value matches the output
compare register B (OCR1B).
Note that a forced output compare (1B) strobe will not set the OCF1B flag.
OCF1B is automatically cleared when the output compare match B interrupt vector is exe-
cuted. Alternatively, OCF1B can be cleared by writing a logical one to its bit location.
• Bit 1– OCF1A: Timer/Counter1, Output Compare A Match Flag
This flag is set in the timer clock cycle after the counter (TCNT1) value matches the output
compare register A (OCR1A).
Note that a forced output compare (1A) strobe will not set the OCF1A flag.
OCF1A is automatically cleared when the output compare match A interrupt vector is exe-
cuted. Alternatively, OCF1A can be cleared by writing a logical one to its bit location.
• Bit 0– TOV1: Timer/Counter1, Overflow Flag
The setting of this flag is dependent of the WGM13:0 bit settings. In normal and CTC modes,
the TOV1 flag is set when the timer overflows. See Table 14-4 on page 115 for the TOV1 flag
behavior when using another WGM13:0 bit setting.
TOV1 is automatically cleared when the timer/counter 1 overflow interrupt vector is executed.
Alternatively, TOV1 can be cleared by writing a logical one to its bit location.
Bit 765432 10
0x0B (0x2B) – – ICIF1 – – OCF1B OCF1A TOV1 TIFR1
Read/Write R R R/W R R R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0