DMA Controller
12-55
Peripherals
Table 12–6. DMA Global-Control Register Bits Summary (Continued)
Abbreviation
Reset
Value
Name
Description
INCSRC
0
DMA source address
increment mode
If INCSRC = 1, the source address is incremented after every
read.
DECSRC
0
DMA source address
decrement mode
If DECSRC = 1, the source address is decremented after
every read.
If INCSRC = DECSRC, the source address is not modified
after a read.
INCDST
0
DMA destination
address increment
mode
If INCDST = 1, the destination address is incremented after
every write.
DECDST
0
DMA destination
address decrement
mode
If DECDST = 1, the destination address is decremented after
every write.
If INCDST = DECDST, the destination address is not modified
after a write.
SYNC
0
DMA synchronization
mode
Determines the timing synchronization between the events
initiating the source and destination transfers.
The following table summarizes the SYNC bits and DMA
synchronization.
Bit 9
Bit 8
Function
0
0
No synchronization. Enabled interrupts
are ignored (reset value).
0
1
Source synchronization. A read is per-
formed when an enabled interrupt occurs.
1
0
Destination synchronization. A write is per-
formed when an enabled interrupt occurs.
1
1
Source and destination synchronization. A
read is performed when an enabled interrupt
occurs. A write is then performed when the
next
enabled interrupt occurs.
TC
0
DMA transfer mode
Affects the operation of the transfer counter.
If TC = 0, transfers are not terminated when the transfer
counter becomes 0.
If TC = 1, transfers are terminated when the transfer
counter becomes 0.
TCINT
0
DMA transfer counter
interrupt mode
If TCINT = 1, the DMA interrupt is set when the transfer
counter makes a transition to 0.
If TCINT = 0, the DMA interrupt is not set when the transfer
counter makes a transition to 0.