Visible to Intel only — GUID: nik1409773846886
Ixiasoft
Visible to Intel only — GUID: nik1409773846886
Ixiasoft
2.1.1.1. Dedicated refclk Pins
There are two dedicated refclk pins available in each GT transceiver bank. The two refclk pins can also provide the reference clocks to the GX channels in a GT transceiver bank through the reference clock network.
Power pins associated with transceiver banks must be powered up. At least one transceiver must be instantiated in the design if a dedicated transceiver refclk pin is used as a clock reference for a core fPLL.
The following table lists the electrical specifications for the input reference clock signal driven on the refclk pins.
Protocol | I/O Standard | Coupling | Termination |
---|---|---|---|
PCI Express (PCIe) |
|
AC | On - Chip 1 |
|
DC | Off - Chip 3 | |
All other protocols |
|
AC | On - Chip 1 |
set_instance_assignment -name XCVR_REFCLK_PIN_TERMINATION_DC_COUPLING_EXTERNAL_RESISTOR -to <refclk_pin_name>
- No biasing is required if the reference clock signals are generated from a clock source that conforms to the PCIe specification
- Select Rs and / or Rp resistor values as recommended by the PCIe clock source vendor.