R-tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide
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2.4.1. Clocking
In PIPE Direct mode, the PCS, Data Link Layer and Transaction Layer inside the R-tile IP for PCIe are not active. The only clock domains are pipe_direct_pld_tx_clk_out_o and lnX_pipe_direct_pld_rx_clk_out_o, which are clock outputs from the R-tile PHY layer to the FPGA fabric.
Mode | PHY Clock Frequency | Application Clock Frequency |
---|---|---|
PIPE Direct | TX: 1000 MHz | TX: 500 MHz |
RX: Gen1: 250 MHz Gen2: 500 MHz Gen3: 250 MHz Gen4: 500 MHz Gen5: 1000 MHz |
RX: Gen1: 125 MHz Gen2: 250 MHz Gen3: 125 MHz Gen4: 250 MHz Gen5: 500 MHz |
R-tile has two reference clock inputs at the package level, refclk0 and refclk1.
You must connect a 100 MHz reference clock source to these two inputs. In PIPE Direct mode, you must drive the two refclk inputs from the same clock source. However, if Octet 1 is not used, refclk1 can be tied to ground.