The ALT_OUTBUF_DIFF primitive allows you to name and connect positive and negative pins when a differential I/O standards Definition is applied to an output pin. This primitive allows you to do the following:

  • Make a location assignment
  • Make an I/O standards Definition assignment
  • Make a drive strength (current strength) assignment
  • Enable bus-hold circuitry
  • Enable a weak pull-up resistor
  • Make slow slew rate assignments
  • Make an on-chip termination (OCT) assignment to an input pin from a lower-level entity

This primitive is available for Cyclone® III and Stratix® III device families only.

  • Trying to set other parameters not listed in the Parameters table on the ALT_OUTBUF_DIFF primitive results in errors.
  • For information about Intel® Quartus® Prime primitive instantiation, go to Using a Intel® Quartus® Prime Logic Function.