Why do the clock frequencies in the ALTLVDS_TX megafunction different than those I enter in MegaWizard Plug-In Manager? - Why do the clock frequencies in the ALTLVDS_TX megafunction different than those I enter in MegaWizard Plug-In Manager? Description Due to a problem in the Quartus® II software versions 10.0 and later, megafunctions generated with the ALTLVDS_TX MegaWizard™ Plug-In Manager may include clock frequencies that do not match what you enter for the What is the output data rate? parameter. This problem only affect Windows 64-bit operating systems. To confirm that the Nominal VCO frequency for the ALTLVDS_TX PLL matches your data rate, follow these steps: In the Compilation Report, expand Fitter Expand Resource Section Check the PLL Summary To work around this problem, perform the following steps: Close the Quartus II software. Append %QUARTUS_ROOTDIR%\bin64 to the User environment variable PATH . Restart the Quartus II software to use ALTLVDS_TX MegaWizard Plug-In Manager. This problem is fixed beginning with the Quartus II software version 11.0. Related Articles Why does the ALTLVDS_RX MegaWizard only show an input clock frequency of 100 MHz? Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']