Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet

Product codes
MEGA328P-XMINI
Page of 657
159
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
• 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.
18.11.7 TIFR2 – Timer/Counter2 Interrupt Flag Register
• Bit 2 – OCF2B: Output Compare Flag 2 B
The OCF2B bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2B 
– Output Compare Register2. OCF2B is cleared by hardware when executing the corresponding interrupt 
handling vector. Alternatively, OCF2B is cleared by writing a logic one to the flag. When the I-bit in SREG, 
OCIE2B (Timer/Counter2 Compare match Interrupt Enable), and OCF2B are set (one), the Timer/Counter2 
Compare match Interrupt is executed.
• Bit 1 – OCF2A: Output Compare Flag 2 A
The OCF2A bit is set (one) when a compare match occurs between the Timer/Counter2 and the data in OCR2A 
– Output Compare Register2. OCF2A is cleared by hardware when executing the corresponding interrupt 
handling vector. Alternatively, OCF2A is cleared by writing a logic one to the flag. When the I-bit in SREG, 
OCIE2A (Timer/Counter2 Compare match Interrupt Enable), and OCF2A are set (one), the Timer/Counter2 
Compare match Interrupt is executed.
• Bit 0 – TOV2: Timer/Counter2 Overflow Flag
The TOV2 bit is set (one) when an overflow occurs in Timer/Counter2. TOV2 is cleared by hardware when 
executing the corresponding interrupt handling vector. Alternatively, TOV2 is cleared by writing a logic one to 
the flag. When the SREG I-bit, TOIE2A (Timer/Counter2 Overflow Interrupt Enable), and TOV2 are set (one), 
the Timer/Counter2 Overflow interrupt is executed. In PWM mode, this bit is set when Timer/Counter2 changes 
counting direction at 0x00.
18.11.8 ASSR – Asynchronous Status Register
• Bit 7 – Reserved
This bit is reserved and will always read as zero.
• Bit 6 – EXCLK: Enable External Clock Input
When EXCLK is written to one, and asynchronous clock is selected, the external clock input buffer is enabled 
and an external clock can be input on Timer Oscillator 1 (TOSC1) pin instead of a 32kHz crystal. Writing to 
Bit
7
6
5
4
3
2
1
0
OCF2B
OCF2A
TOV2
TIFR2
Read/Write
R
R
R
R
R
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
EXCLK
AS2
TCN2UB
OCR2AUB
OCR2BUB
TCR2AUB
TCR2BUB
ASSR
Read/Write
R
R/W
R/W
R
R
R
R
R
Initial Value
0
0
0
0
0
0
0
0