Why has the disable_chainout signal been removed in the Native Fixed Point DSP Agilex™ FPGA starting in version 24.3.1 of the Quartus® Prime Pro Edition Software?

Description

The dynamic chainout feature for fixed-point DSP is an advanced feature not officially supported in the Agilex™ 7 & 5 devices.

The fixed-point DSP dynamic chainout feature has timing violations that are not identified by the Quartus® Prime Pro software.

Resolution

Customers are advised to remove any connections to the disable_chainout port and recompile designs in the Quartus® Prime Pro Edition Software version 24.3.1 or later.

The removal of this signal has been officially documented in the v3.0.0 Native Fixed Point DSP Agilex™ FPGA IP Release Notes.

Additional Information

For the Agilex™ 7 and Agilex™ 5 FPGA design developed in the Quartus® Prime Pro Edition Software before version 24.3, customers are advised to run the risk assessment script to ascertain if their design is impacted.

Steps to run the script:

1. Run EDA Netlist Writer with the successfully pre-compiled design.
2. Insert the risk assessment script in the Quartus project folder
3. Navigate to the Quartus project folder:  cd <quartus project path> 
4. Run the command: tclsh screening.tcl ./simulation/questa/<project_name>.vo
5. Follow the message prompted for the next step.

Related Articles

Error: The dynamic chainout feature for fixed-point DSP is an advanced feature not supported in the current release. Disconnect the disable_chainout port and contact Altera for details.

Release Note for Native Fixed Point DSP Agilex™ 7 FPGA IP v20.0.0

Release Note for Native Fixed Point DSP Agilex™ 5 FPGA IP v3.0.0