4.1.1. QSF Assignments for Reference Clock Pins
Refer to the Intel Stratix 10 Device Family Pin Connection Guidelines for how to
connect unused reference clock pins.
Table 39.
QSF Assignments for a Single Reference Clock Pin (refclk[0])
You must manually include these QSF settings for every used reference clock pin.
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]
Select 3.3V
tolerant
instead of 2.5V
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]
(10)
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: Always DISABLE it as long as the reference clock
characteristic meets the specification in the Intel Stratix 10 Device
Datasheet.
Set reference
clock
frequency
freq_in_MHz
= "legal
value"
set_instance_assignment -name HSSI_PARAMETER
"refclk_divider_input_freq=freq_in_MHz" -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.
Related Information
•
Intel Stratix 10 Device Datasheet
•
Intel Stratix 10 Device Family Pin Connection Guidelines
4.2. Core Clock Network Use Case
These use cases provide guidance about how you can connect various clocks through
the GUI for different use cases.
(10)
Refer to the Intel Stratix 10 Device Datasheet for the reference clock voltage rating electrical
specifications.
(11)
Refer to the Intel Stratix 10 Device Datasheet for the reference clock frequency specification.
4. Clock Network
UG-20056 | 2019.02.04
Intel
®
Stratix
®
10 E-Tile Transceiver PHY User Guide
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