IP100A 查看數據表（PDF） - Unspecified

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IP100A

Integrated 10/100 Ethernet MAC + PHY

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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

RFD

RxDMANextPtr

RxFrameStatus

1st RxDMAFragAddr

1st RxDMAFragLen

2nd RxDMAFragAddr

2nd RxDMAFragLen

Last RxDMAFragAddr

Last RxDMAFragLen

1st Data Frag (Buffer)

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.

Copyright © 2004, IC Plus Corp.

20/97

March. 30, 2007

IP100A LF-DS-R17

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