Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 120

AGB Programming Manual
DMA3CNT_H [d09] DMA Repeat
With the DMA repeat function set to ON, if V-blanking or H-blanking
intervals are selected as the timing of DMA startup, DMA is restarted when
the next startup condition occurs (a V-blank or H-blank). In this mode,
restarting will continue as long as the DMA enable flag is not set to 0.
When the DMA repeat function is set to OFF, DMA halts as soon as the
amount of data specified by the value in the word-count register has been
transferred.
However, in Game Pak data request mode do not use the repeat function.
DMA3CNT_H [d08] Source Address Control Flag
Control of the source address is specified after each DMA transfer.
A setting of 00 causes an increment.
A setting of 01 causes a decrement.
A setting of 10 causes it to be fixed.
11 is a prohibited code.
When the Game Pak Bus has been set to the source address, make sure
you select increment.
DMA3CNT_H [d07] Destination Address Control Flag
Control of the destination address is specified after each DMA transfer.
A setting of 00 causes an increment.
A setting of 01 causes a decrement.
A setting of 10 causes it to be fixed.
A setting of 11 causes an increment to be carried out and then a reload
(returned to setting at start of transfer) is done after every transfer is
completed.
©1999 - 2001 Nintendo of America Inc.
120
DMA Transfer
D.C.N. AGB-06-0001-002B4