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/
838
Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
25.5.48
ETH DMA operation mode register (ETH_DMAOPMOD)
Address offset: 0x1018
Reset value: 0x0000 0000
This register sets the working mode and command for receiving and sending. This register should be written last in
the entire DMA initialization process.
Bit field
Name
Description
31:27
Reserved
Reserved, the reset value must be maintained.
26
DT
Do not drop TCP/IP checksum error frames.
0: If ETH_DMAOPMOD.FEF is 0, MAC discards all erroneous frames.
1: If the received frame has only checksum errors, MAC will not discard the frame.
25
RSF
Receive store-and-forward.
0: RxFIFO works in cut-through (threshold) mode, and the forwarding threshold is
determined by these bits of ETH_DMAOPMOD.RTC[1:0].
1: RxFIFO works in store-and-forward mode. Only after the frame is completely
written to RxFIFO, RxDMA will forward it to the application, and the value of
ETH_DMAOPMOD.RTC will be ignored.
24
DFF
Do not clear received frames.
0: When the receive descriptor is not available (or the receive buffer is not available),
the RxDMA empties the receive frame in the RxFIFO.
1: RxDMA does not clear receive frames, even if receive descriptors are not available
(or receive buffers are not available).
23:22
Reserved
Reserved, the reset value must be maintained.
21
TSF
Transmit store-and-forward.
0: TxFIFO works in cut-through (threshold) mode, and the transmit threshold is
determined by these bits of ETH_DMAOPMOD.TTC[2:0].
1: TxFIFO works in store-and-forward mode. Only after the frame is completely
written to TxFIFO, MAC will transmit it out. At this time, the value of
ETH_DMAOPMOD.TTC will be ignored.
Note: This bit can only be modified when the transmission is stopped.
20
FTF
Clear TxFIFO.
When this bit is set to 1, TxFIFO control logic is reset to its initial state, so that all
data in the TxFIFO is emptied/lost. This bit is automatically cleared to 0 after the
clear operation is complete. Writing to this register is not allowed until this bit is 0.
19:17
Reserved
Reserved, the reset value must be maintained.