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IP100A LF
Preliminary Data Sheet
linked list of frame descriptors, called RFDs. RFDs contain pointers to the fragment buffers into which the
IP100A LF is to place receive data, as shown in Figure 6.
HOST SYSTEM MEMORY
RxDMANextPtr
RxFrameStatus
1st RxDMAFragAddr
1st RxDMAFragLen
2nd RxDMAFragAddr
2nd RxDMAFragLen
Last RxDMAFragAddr
Last RxDMAFragLen
1st Data Frag (Buffer)
RFD
2nd Data Frag (Buffer)
Last Data Frag (Buffer)
FIGURE 6: RxDMA Data Structure
The RFD format is covered in the Registers and Data Structures section.
Similar to TFDs, the resulting linked list of RFDs is referred to as the RxDMAList. One option available to
RxDMA that differs from TxDMA is that the RxDMAList can be formed into a ring as shown in Figure 7. A
host system can allocate a number of full size frame buffers, create a RFD for each one, and link the
RFDs into a circular list. As frames are received and transferred by RxDMA, a RxDMAComplete interrupt
will be generated for each frame.
March. 30, 2007
20/97
Copyright © 2004, IC Plus Corp.
IP100A LF-DS-R17
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