Forum Discussion
New ContributorVideo generation with altlvds_tx and external PLL
I fixed it.
It was a case of RTFM - the 'slow' clock input to the atltlvds_tx block needs to be half the pixel clock frequency, I found this buried in the timing reports from the old design. Once I reconfigured the PLL again to give a third output at 36 MHz, it all works perfectly and passes timing.
This info is also in an information panel in the MegaWizard GUI, I didn't see it the first time.
New ContributorI fixed it.
It was a case of RTFM - the 'slow' clock input to the atltlvds_tx block needs to be half the pixel clock frequency, I found this buried in the timing reports from the old design. Once I reconfigured the PLL again to give a third output at 36 MHz, it all works perfectly and passes timing.
This info is also in an information panel in the MegaWizard GUI, I didn't see it the first time.
