DS537 Datasheet, PDF (71/148 Pages) Xilinx, Inc – LogiCORE IP XPS LL TEMAC

LogiCORE IP XPS LL TEMAC (v2.03a)
Functional Description
A LocalLink interface transfers data in one direction only. Each Ethernet interface will use one LocalLink interface
for transmit frames and another LocalLink interface for receive frames. If both Ethernet interfaces in an
XPS_LL_TEMAC are used, 4 total LocalLink interfaces will be used for data transfer.
The LocalLink interfaces used in this implementation are 32-bits wide, have side-band control signals, and will
typically operate with a clock between 100 and 125 MHz.
Data is transferred across the LocalLink in frames which are composed of a header, a payload, and a footer. The
payload contains the actual frame data while the header and footer contain mode and control information. The
definition of the header and footer is different for the transmit and receive data paths.
For the transmit data path the "Source" will be the embedded system, typically a DMA controller, and the
"Destination" will be the XPS_LL_TEMAC. For the receive data path the "Source" will be the XPS_LL_TEMAC and
the "Destination" will be the embedded system, typically a DMA controller.
Control signals are used to mark the header, payload, and footer phases of the frame as well as to signal the
readiness of the Source and Destination and to indicate which bytes in the 32-bit path contain valid data.
Figure 46 shows an example of the LocalLink waveforms for a transmit Ethernet frame when both Source and
Destination are always ready. If either becomes unready during the transfer, the waveform is extended until the
ready signal is re-asserted.
Figure 47 shows an example of the LocalLink waveforms for a receive Ethernet frame when both Source and
Destination are always ready. If either becomes unready during the transfer, the waveform is extended until the
ready signal is re-asserted.
X-Ref Target - Figure 46
LlinkTemac_CLK
LlinkTemac_RST
LlinkTemac_Data(0:31)
Header
Payload (variable) FTR
LlinkTemac_SRC_RDY_n
TemacLlink_DST_RDY_n
LlinkTemac_REM(0:3)
REM
REM
REM REM
LlinkTemac_SOF_n
LlinkTemac_SOP_n
LlinkTemac_EOP_n
LlinkTemac_EOF_n
DS537_46_091909
Figure 46: Typical Waveform of LocalLink Transmit Ethernet Frame
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