Datasheet

141
ATmega48PA/88PA/168PA [DATASHEET]
9223F–AVR–04/14
18.11.3 TCNT2 – Timer/Counter Register
The Timer/Counter register gives direct access, both for read and write operations, to the Timer/Counter unit 8-bit counter.
Writing to the TCNT2 Register blocks (removes) the compare match on the following timer clock. Modifying the counter
(TCNT2) while the counter is running, introduces a risk of missing a compare match between TCNT2 and the OCR2x
Registers.
18.11.4 OCR2A – Output Compare Register A
The output compare register A contains an 8-bit value that is continuously compared with the counter value (TCNT2). A
match can be used to generate an output compare interrupt, or to generate a waveform output on the OC2A pin.
18.11.5 OCR2B – Output Compare Register B
The output compare register B contains an 8-bit value that is continuously compared with the counter value (TCNT2). A
match can be used to generate an output compare interrupt, or to generate a waveform output on the OC2B pin.
18.11.6 TIMSK2 – Timer/Counter2 Interrupt Mask Register
• Bit 2 – OCIE2B: Timer/Counter2 Output Compare Match B Interrupt Enable
When the OCIE2B bit is written to one and the I-bit in the status register is set (one), the Timer/Counter2 compare match B
interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, i.e., when the
OCF2B bit is set in the Timer/Counter 2 interrupt flag register – TIFR2.
• Bit 1 – OCIE2A: Timer/Counter2 Output Compare Match A Interrupt Enable
When the OCIE2A bit is written to one and the I-bit in the status register is set (one), the Timer/Counter2 compare match A
interrupt is enabled. The corresponding interrupt is executed if a compare match in Timer/Counter2 occurs, i.e., when the
OCF2A bit is set in the Timer/Counter 2 interrupt flag register – TIFR2.
• Bit 0 – TOIE2: Timer/Counter2 Overflow Interrupt Enable
When the TOIE2 bit is written to one and the I-bit in the status register is set (one), the Timer/Counter2 Overflow interrupt is
enabled. The corresponding interrupt is executed if an overflow in Timer/Counter2 occurs, i.e., when the TOV2 bit is set in
the Timer/Counter2 interrupt flag register – TIFR2.
Bit 76543210
(0xB2) TCNT2[7:0] TCNT2
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
(0xB3) OCR2A[7:0] OCR2A
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
(0xB4) OCR2B[7:0] OCR2B
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543 2 1 0
(0x70) –––––OCIE2BOCIE2ATOIE2TIMSK2
Read/WriteRRRRRR/WR/WR/W
Initial Value00000 0 0 0