
S3C3410X RISC MICROPROCESSOR
DMA
6-7
DMACONx
Bit
Description
Initial State
SF
[7]
Source Address Fix: This bit determines whether the source
address should be changed during a DMA operation, or not. If
users take SF option, the source address will be fixed.
0 = Increase/Decrease source address
1 = Do not change source address (fix)
0
SI
[8]
Stop Interrupt Enable: The DMA operation can be started by
setting RE bit to "1" and can also be stopped by resetting RE bit
to "0". When this SI bit is set to "1", and when the DMA
operation is forced to stop, there will be "stop interrupt"
generation. If this bit is "0", the "stop interrupt" will not be
generated. The DMA done interrupt, which is generated after the
DMA counter is expired, can not be masked by this bit.
0 = Do not generate the stop interrupt when DMA stops
1 = Generate the stop interrupt when DMA stops
0
BT (note)
[9]
4 Burst Enable: When the MODE bit is set to "1" , the DMA
operation will be done by the burst transfer mode. The size of
burst will depend on TW field in this register. If TW is word unit,
there will be four times word transfer.
0 = Normal transfer
1 = 4 Burst transfer
0
Reserved
[10]
Reserved
0
SB
[11]
Single/Block Mode: This bit determines the number of external
DMA request (nDREQ) that are required for the DMA operation.
0 = One nDREQ initiates a single DMA operation
1 = One nDREQ initiates a block DMA operation
0
TW
[13:12]
Transfer Width: This bit determines the transfer data width:
byte(8-bit), half-word(16-bit) and word(32-bit).
If the transfer width is a byte, source/destination address will be
increased/decreased by one(Byte address unit), If it is a half-
word, the address will be increased/decreased by two(Half-word
address unit). If it is a word, the address will be
increased/decreased by four(Word address unit). Note that the
"transfer width" is not the physical size of data bus. The physical
size of data bus is determined by SMR(System Manager
Register) configuration.
00 = Byte(8-bit)
01 = Half-word(16-bit)
10 = Word(32-bit)
11 = Not used
00