64
8331B–AVR–03/12
Atmel AVR XMEGA AU
• 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.
• Bit 5:4 – SRCDIR[1:0]: Channel Source Address Mode
These bits decide the DMA channel source address mode according to
. These bits
cannot be changed if the channel is busy.
• Bit 3:2 – DESTRELOAD[1:0]: Channel Destination Address Reload
These bits decide the DMA channel destination address reload according to
. These bits cannot be changed if the channel is busy.
• Bit 1:0 – DESTDIR[1:0]: Channel Destination Address Mode
These bits decide the DMA channel destination address mode according to
. These bits cannot be changed if the channel is busy.
Table 5-5.
DMA channel source address reload settings.
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.
Table 5-6.
DMA channel source address mode settings.
SRCDIR[1:0]
Group Configuration
Description
00
FIXED
Fixed
01
INC
Increment
10
DEC
Decrement
11
-
Reserved
Table 5-7.
DMA channel destination address reload settings.
DESTRELOAD[1:0]
Group Configuration
Description
00
NONE
No reload performed.
01
BLOCK
DMA channel destination address register is reloaded
with initial value at end of each block transfer.
10
BURST
DMA channel destination address register is reloaded
with initial value at end of each burst transfer.
11
TRANSACTION
DMA channel destination address register is reloaded
with initial value at end of each transaction.