Visible to Intel only — GUID: gjn1529606914308
Ixiasoft
Visible to Intel only — GUID: gjn1529606914308
Ixiasoft
4.1.1. QSF Assignments for Reference Clock Pins
Description | Value | QSF Assignment |
---|---|---|
Set reference clock IO standard | differential LVPECL | set_instance_assignment -name IO_STANDARD "DIFFERENTIAL LVPECL" -to <refclk_name> -entity <block_name> |
Enable on-die termination resistors | enable_term = (on-chip termination on) disable_term = (on-chip termination off) |
set_instance_assignment -name HSSI_PARAMETER "refclk_divider_enable_termination=enable_term" -to ref_clk[0] Recommendation: Set this to enable_term unless external on-board termination is used and internal termination is supposed to be bypassed. |
Select 3.3 V tolerant instead of 2.5 V | enable_3p3v_tol = (3.3V) disable_3p3v_tol = (2.5V) |
set_instance_assignment -name HSSI_PARAMETER "refclk_divider_enable_3p3v=enable_3p3v_tol" -to ref_clk[0] 35 Recommendation: Set this to disable_3p3v_tol unless the clock source is compliant to LVPECL 3.3v standard. |
Enable LVPECL driver hysteresis | enable_hyst = (hysteresis on) disable_hyst = (hysteresis off) |
set_instance_assignment -name HSSI_PARAMETER "refclk_divider_disable_hysteresis=enable_hyst" -to ref_clk[0] Recommendation: Set this to disable_hyst provided that the reference clock characteristic meets the specification in the Device Data Sheet. |
Set reference clock frequency | freq_in_Hz = "legal value" | set_instance_assignment -name HSSI_PARAMETER "refclk_divider_input_freq=freq_in_Hz" -to ref_clk[0] Recommendation: Use the same reference clock frequency number as in the respective transceiver IP. |
Power down LVPECL driver | false = (driver on) true = (driver off) |
set_instance_assignment -name HSSI_PARAMETER "refclk_divider_powerdown_mode=false" -to ref_clk[0] Recommendation: If you plan to use the target reference clock, set this to false. |