Intel® Agilex™ F-Series and I-Series General-Purpose I/O User Guide

ID 683780
Date 6/14/2022
Document Table of Contents

6.2.5. QSF Assignments

Intel® Agilex™ devices support the following termination-related Intel® Quartus® Prime settings file (.qsf) assignments:

Table 60.  QSF Assignments
QSF Assignment Details


The input/output termination assignment specifies the termination value in ohm on the pin in question.


set_instance_assignment -name INPUT_TERMINATION <value> -to <pin name>
set_instance_assignment -name OUTPUT_TERMINATION <value> -to <pin name>

To enable the series/parallel termination ports, include these assignments, which specify the series and parallel termination values for the pins.

Make sure to connect the ser_data port from the OCT Intel® FPGA IP to the GPIO Intel® FPGA IP.

set_instance_assignment -name INPUT_TERMINATION "PARALLEL <VALUE> OHM WITH CALIBRATION" -to <pin>
set_instance_assignment -name OUTPUT_TERMINATION "SERIES <VALUE> OHM WITH CALIBRATION" -to <pin>

Directs the Fitter to make the proper connection from the desired OCT block to the specified pins. This assignment is useful when I/O buffers are not explicitly instantiated and you need to associate the pins with a specific OCT block.


set_instance_assignment -name TERMINATION_CONTROL_BLOCK <desired OCT BLK> -to <pin name>

The Fitter searches for the rzq pin name in the netlist. If the pin does not exist, the Fitter creates the pin name along with the OCT IP and its corresponding connections. This allows you to create a group of pins to be calibrated by an existing or non-existing OCT and the Fitter ensures the legality of the design.


set_instance_assignment -name RZQ_GROUP <rzq pin name> -to <pin name>

Termination can exist on input and output buffers, and sometimes simultaneously.

There are two methods to associate pin groups with an OCT block:

  • Use a .qsf assignment to indicate which pin (bus) is associated with which OCT block. You can use the TERMINATION_CONTROL_BLOCK assignment to associates a pin with an OCT instantiated in the RTL.
  • Instantiate the I/O buffer primitives at the top level and connect them to the appropriate OCT blocks.
Figure 48. OCT Block Connection with I/O BufferThis figure shows the connections from the I/O buffer primitives to the appropriate OCT blocks.
Note: All I/O banks within the same bank row with the same VCCIO can share one OCT block even if that particular I/O bank has its own OCT block. You can connect any number of I/O pins that support calibrated termination to an OCT block. Ensure that you connect I/Os with compatible configuration to an OCT block. You must also ensure that the OCT block and its corresponding I/Os have the same VCCIO and series or parallel termination values. With these settings, the Fitter places the I/Os and OCT block in the same column. The Intel® Quartus® Prime software generates warning messages if there is no pin connected to the block.

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