Overview Of Locallink Interface; Data Flow; Figure A-2: Frame Transfer Across Locallink Interface; Figure A-3: Frame Transfer With Flow Control - Xilinx LogiCORE IP MAC v8.5 User Manual

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Overview of LocalLink Interface

Data Flow

Data is transferred on the LocalLink interface from source to destination, with the flow
being governed by the four active low control signals sof_n, eof_n, src_rdy_n, and
dst_rdy_n. The flow of data is controlled by the src_rdy_n and dst_rdy_n signals.
Only when these signals are asserted simultaneously is data transferred from source to
destination. The individual packet boundaries are marked by the sof_n and eof_n
signals. For more information on the LocalLink interface see to Xilinx Application Note
XAPP691, "Parameterizable LocalLink FIFO" available at
direct.xilinx.com/bvdocs/appnotes/xapp691.pdf.
Figure A-2
Figure A-3
dst_rdy_n signals are used to control the flow of data across the interface.
130
-- DISCONTINUED PRODUCT --
shows the transfer of an 8-byte frame.
clock
data[7:0] 0 1
sof_n
eof_n
src_rdy_n
dst_rdy_n

Figure A-2: Frame Transfer across LocalLink Interface

illustrates frame transfer of a 5-byte frame, where both the src_rdy_n and
clock
data[7:0] 0
sof_n
eof_n
src_rdy_n
dst_rdy_n

Figure A-3: Frame Transfer with Flow Control

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Appendix A: Using the Client-Side FIFO
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1-Gigabit Ethernet MAC v8.5 User Guide
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UG144 April 24, 2009