Device Family: Stratix® IV E, Stratix® IV GT, Stratix® IV GX

Type: Answers

Area: EMIF, Intellectual Property

IP Product: DDR3 SDRAM Controller MegaCore supporting UniPHY

Error: The specified Memory clock frequency exceeds the Memory device speed grade of 533.333 MHz. Please increase the Memory device speed grade (in Memory Parameters tab) or decrease the Memory clock frequency.


You may see the above error when generating a Stratix IV DDR3 UniPHY controller in the Quartus® II software version 13.1 or later. There is a new frequency check in the MegaWizard™ Plug-in Manager IP GUI that prevents users from running the interface faster than the maximum supported frequency. If you specify the maximum supported frequency with more than 3 decimal places (i.e. 533.3333MHz), it will lead to the above error.


The workaround is to limit the DDR3 Memory clock frequency in the PHY Settings tab of the MegaWizard™ Plug-In Manager to three decimal places.