Sundance Spas ST201 - Manual (Page 69)

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Sundance Technology ST201 PRELIMINARY draft 2
DMACTRL
Class....................I/O Registers, DMA
Base Address ......IoBaseAddress register value
Address Offset .....0x00
Access Mode .......Read/Write
Width ...................32 bits
DMACtrl controls some of the bus master functions in the RxDMA and TxDMA engines, and contains sta-
tus bits. DMACtrl is cleared by a reset.
BIT BIT NAME BIT DESCRIPTION
0 RxDMAHalted This read-only bit is set whenever RxDMA is halted by setting the RxD-
MAHalt bit or an implicit halt due to fetching a RFD with RxDMACom-
plete in ReceiveFrameStatus already set. Cleared by setting the
RxDMAResume bit.
1 TxDMACmplReq This read-only bit is set to the value from the TxDMAIndicate field in
the TFC of the current TFD.
2 TxDMAHalted This read-only bit is set whenever TxDMA is halted by setting the TxD-
MAHalt bit. Cleared by setting the TxDMAResume bit.
3 RxDMAComplete This read-only bit is the same as RxDMAComplete in IntStatus. This bit
is different from the RxDMAComplete bit in RxDMAStatus, which is a
real time indication of frame RxDMA completion and is cleared when a
new frame RxDMA begins. This bit is latched once a frame RxDMA
completion has occurred. This bit is cleared by acknowledgment to the
RxDMAComplete bit in the IntStatus register.
4 TxDMAComplete This read-only bit is the same as TxDMAComplete in IntStatus. This bit
is cleared by acknowledgment to the TxDMAComplete bit in the IntSta-
tus register.
7..5 Reserved Reserved for future use. Should be set to 0.
8 RxDMAHalt Whenever this bit is set, the RxDMA is halted. This bit is self-clearing
and writing a 0 into this bit is ignored.
9 RxDMAResume Whenever this bit is set, the RxDMA is resumed. This bit is self-clear-
ing and writing a 0 into this bit is ignored.
10 TxDMAHalt Whenever this bit is set, the TxDMA is halted. This bit is self-clearing
and writing a 0 into this bit is ignored.
11 TxDMAResume Whenever this bit is set, the TxDMA is resumed. This bit is self-clearing
and writing a 0 into this bit is ignored.
13..12 Reserved Reserved for future use. Should be set to 0.
14 TxDMAInProg This read-only bit indicates that a TxDMA operation is in progress. This
bit is primarily used by drivers in an under run recovery routine since
the driver needs waits for this bit to be cleared before issuing the TxRe-
set to clear the under run condition. Before checking TxDMAInProg,
issue TxDMAHalt to ensure that TxDMAInProg is not set as a result of
the ST201 being in a polling mode.