Datasheet

91
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
12.8.6 Timer/Counter Interrupt Mask Register – TIMSK0
• Bits 7..3 – Res: Reserved Bits
These bits are reserved bits in the Atmel
®
ATmega48/88/168 and will always read as zero.
• Bit 2 – 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 – 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 0 – 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 interrupt flag register – TIFR0.
12.8.7 Timer/Counter 0 Interrupt Flag Register – TIFR0
• Bits 7..3 – Res: Reserved Bits
These bits are reserved bits in the Atmel ATmega48/88/168 and will always read as zero.
• Bit 2 – OCF0B: Timer/Counter 0 Output Compare B Match Flag
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 corresponding 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 1 – OCF0A: Timer/Counter 0 Output Compare A Match Flag
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 corresponding 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 0 – 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.
The setting of this flag is dependent of the WGM02:0 bit setting. Refer to Table 12-8 on page 89 in Section 12-8 “Waveform
Generation Mode Bit Description” on page 89.
Bit 7 6 5 4 3 2 1 0
– – – – – OCIE0B OCIE0A TOIE0 TIMSK0
Read/Write R R R R R R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
–––––OCF0BOCF0ATOV0TIFR0
Read/Write RRRRRR/WR/WR/W
Initial Value00000000