Why does the Quartus II fitter report display "unused" in the Termination column when applying the LVDS I/O standard to REFCLK pins in Intel® Arria®10 devices?

Description

Due to a bug in Quartus® II software version 14.1, the fitter report displays "unused" in the Termination column of Intel Arria 10 devices when both of the following conditions are true:

• Applying the LVDS I/O standard to the dedicated REFCLK pins
• Setting the dedicated REFCLK pin XCVR_A10_REFCLK_TERM_TRISTATE = TRISTATE_OFF .qsf assignment

The fitter report should display tristate_off.

Resolution