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XMEGA B [DATASHEET]
8291B–AVR–01/2013
Bit 6 – CHPEND: Channel Pending
If a block transfer is pending on the DMA channel, the CHPEND flag will be read as one. This flag is automatically
cleared when the transfer starts or if the transfer is aborted.
Bit 5 – ERRIF: Error Interrupt Flag
If an error condition is detected on the DMA channel, the ERRIF flag will be set and the optional interrupt is generated.
Since the DMA channel error interrupt shares the interrupt address with the DMA channel n transaction complete
interrupt, ERRIF will not be cleared when the interrupt vector is executed. This flag is cleared by writing a one to this
location.
Bit 4 – TRNIF: Channel n Transaction Complete Interrupt Flag
When a transaction on the DMA channel has been completed, the TRNIF flag will be set and the optional interrupt is
generated. When repeat is not enabled, the transaction is complete and TRNIFR is set after the block transfer. When
unlimited repeat is enabled, TRNIF is also set after each block transfer.
Since the DMA channel transaction n complete interrupt shares the interrupt address with the DMA channel error
interrupt, TRNIF will not be cleared when the interrupt vector is executed. This flag is cleared by writing a one to this
location.
Bit 3:2 – ERRINTLVL[1:0]: Channel Error Interrupt Level
These bits enable the interrupt for DMA channel transfer errors and select the interrupt level, as described in
and Programmable Multilevel Interrupt Controller” on page 118
. The enabled interrupt will trigger for the conditions when
ERRIF is set.
Bit 1:0 – TRNINTLVL[1:0]: Channel Transaction Complete Interrupt Level
These bits enable the interrupt for DMA channel transaction completes and select the interrupt level, as described in
“Interrupts and Programmable Multilevel Interrupt Controller” on page 118
. The enabled interrupt will trigger for the
conditions when TRNIF is set.
5.14.3 ADDRCTRL – Address Control register
Bit 7:6 – SRCRELOAD[1:0]: Channel Source Address Reload
These bits decide the DMA channel source address reload according to
. A write to these bits is ignored while
the channel is busy.
Table 5-4.
DMA channel source address reload settings
Bit
7
6
5
4
3
2
1
0
SRCRELOAD[1:0]
SRCDIR[1:0]
DESTRELOAD[1:0]
DESTDIR[1:0]
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
SRCRELOAD[1:0]
Group Configuration
Description
00
NONE
No reload performed.
01
BLOCK
DMA source address register is reloaded with initial value at end
of each block transfer.
10
BURST
DMA source address register is reloaded with initial value at end
of each burst transfer.
11
TRANSACTION
DMA source address register is reloaded with initial value at end
of each transaction.
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