Atmel XMEGA B, User Manual

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170 XMEGA B [DATASHEET]
8291B–AVR–01/2013
13.12.10INTFLAGS – Interrupt Flag register

Bit 7:4 – CCxIF: Compare or Capture Channel x Interrupt Flag
The compare or capture interrupt flag (CCxIF) is set on a compare match or on an input capture event on the
corresponding CC channel.
For all modes of operation except for capture, the CCxIF will be set when a compare match occurs between the count
register (CNT) and the corresponding compare register (CCx). The CCxIF is automatically cleared when the
corresponding interrupt vector is executed.
For input capture operation, the CCxIF will be set if the corresponding compare buffer contains valid data (i.e., when
CCxBV is set). The flag will be cleared when the CCx register is read. Executing the interrupt vector in this mode of
operation will not clear the flag.
The flag can also be cleared by writing a one to its bit location.
The CCxIF can be used for requesting a DMA transfer. A DMA read or write access of the corresponding CCx or
CCxBUF will then clear the CCxIF and release the request.

Bit 3:2 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always write these bits to zero
when this register is written.

Bit 1 – ERRIF: Error Interrupt Flag
This flag is set on multiple occasions, depending on the mode of operation.
In the FRQ or PWM waveform generation mode of operation, ERRIF is set on a fault detect condition from the fault
protection feature in the AWeX extention. For timer/counters which do not have the AWeX extention available, this flag is
never set in FRQ or PWM waveform generation mode.
For capture operation, ERRIF is set if a buffer overflow occurs on any of the CC channels.
For event controlled QDEC operation, ERRIF is set when an incorrect index signal is given.
This flag is automatically cleared when the corresponding interrupt vector is executed. The flag can also be cleared by
writing a one to this location.

Bit 0 – OVFIF: Overflow/Underflow Interrupt Flag
This flag is set either on a TOP (overflow) or BOTTOM (underflow) condition, depending on the WGMODE setting.
OVFIF is automatically cleared when the corresponding interrupt vector is executed. The flag can also be cleared by
writing a one to its bit location.
OVFIF can also be used for requesting a DMA transfer. A DMA write access of CNT, PER, or PERBUF will then clear the
OVFIF bit.
Bit 7 6 5 4 3 2 1 0
+0x0C
CCDIF CCCIF CCBIF CCAIF – – ERRIF OVFIF
Read/Write R/W R/W R/W R/W R R R/W R/W
Initial Value 0 0 0 0 0 0 0 0