The device clocks are AC coupled LVDS lines without external termination.
For proper operation internal differential termination must be enabled,
the DQS_BIAS will DC bias the AC coupled signal to VCCO/2 (1.8/2) 0.9V
On the Xilinx PHY the available PLL options depends on the lane rate.
Encoding is:
0 - CPLL
1 - QPLL0
2 - QPLL1
Since the selection of line rate is available from the project also the
PLL selection must be exposed.
Use over-writable parameters from the environment.
e.g.
make JESD_MODE=64B66B RX_RATE=24.75 TX_RATE=12.375 REF_CLK_RATE=375 RX_JESD_L=4 TX_JESD_L=4
make JESD_MODE=64B66B RX_RATE=16.22016 TX_RATE=16.22016 REF_CLK_RATE=245.76 RX_JESD_M=8 RX_JESD_L=2 TX_JESD_M=16 TX_JESD_L=4
make JESD_MODE=8B10B RX_JESD_L=4 RX_JESD_M=8 TX_JESD_L=4 TX_JESD_M=8
Laszlo Nagy
Sergiu Arpadi