Due to some changes in the Quartus® Prime Pro Edition software version 25.3, you may see the following error while running a parallel loopback with an external VCXO design example of the GTS SDI IP generated by a former Quartus version other than 25.3.
- Error: can't read "rx1_clkout_H": no such variable
This problem occurs because some pfd.sdc paths have changed in the Quartus® Prime Pro Edition Software version 25.3.
To work around this problem during design migration from the former Quartus® Prime Pro Edition software version to version 25.3, modify the pfd.sdc file located in rtl/loopback/pfd/ directory.
Changed the following lines:
From :
if { [string match "*profile0*" \$rx_clkout] }
To :
if { [string match "*prof0*" \$rx_clkout] }
A parallel loopback with an external VCXO design example that has been generated in Quartus® Prime Pro Edition software version 25.3 is not affected by this problem.