User's Manual

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DMA CONTROLLER S3C2450X RISC MICROPROCESSOR
9-16
4.9 DMA MASK TRIGGER REGISTER (DMASKTRIG)
Register Address R/W Description Reset Value
DMASKTRIG0 0x4B000020 R/W DMA0 Mask Trigger Register 000
DMASKTRIG1 0x4B000120 R/W DMA1 Mask Trigger Register 000
DMASKTRIG2 0x4B000220 R/W DMA2 Mask Trigger Register 000
DMASKTRIG3 0x4B000320 R/W DMA3 Mask Trigger Register 000
DMASKTRIG4 0x4B000420 R/W DMA4 Mask Trigger Register 000
DMASKTRIG5 0x4B000520 R/W DMA5 Mask Trigger Register 000
DMASKTRIG6 0x4B000620 R/W DMA6 Mask Trigger Register 000
DMASKTRIG7 0x4B000720 R/W DMA7 Mask Trigger Register 000
DMASKTRIGn Bit Description Initial State
STOP [2] Stop the DMA operation.
1 = DMA stops as soon as the current atomic transfer ends. If there
is no current running atomic transfer, DMA stops immediately. The
CURR_TC, CURR_SRC, CURR_DST will be 0.
Note: Due to possible current atomic transfer, “stop” may take several
cycles. The finish of “stopping” operation (i.e., actual stop time) can be
detected by waiting until the channel on/off bit (DMASKTRIGn[1]) is set to
off. This stop is “actual stop”.
0
ON_OFF [1] DMA channel on/off bit.
0 = DMA channel is turned off. (DMA request to this channel is
ignored.)
1 = DMA channel is turned on and the DMA request is handled.
This bit is automatically set to off if we set the DCONn[22] bit to “no
auto reload” and/or STOP bit of DMASKTRIGn to “stop”.
Note that when DCON [22] bit is "no auto reload", this bit becomes
0 when CURR_TC reaches 0. If the STOP bit is 1, this bit becomes
0 as soon as the current atomic transfer finishes.
Note: This bit should not be changed manually during DMA operations
(i.e., this has to be changed only by using DCON [22] or STOP bit.)
0
SW_TRIG [0] Trigger the DMA channel in S/W request mode.
1 = it requests a DMA operation to this controller.
However, note that for this trigger to have effects S/W request
mode has to be selected (DCONn[23]) and channel ON_OFF bit
has to be set to 1 (channel on). When DMA operation starts, this bit
is cleared automatically.
0
NOTE: You can freely change the values of DISRC register, DIDST registers, and TC field of DCON register. Those changes
take effect only after the finish of current transfer (i.e., when CURR_TC becomes 0). On the other hand, any change
made to other registers and/or fields takes immediate effect. Therefore, be careful in changing those registers and
fields.