Why do I see timing violations when using the Arria V 10GBaseR PHY soft PCS?

Description

Due to a problem in Quartus® II software version 13.0 you may see setup or hold timing violations in the soft PCS logic when using the Arria® V device 10GBaseR PHY. This is due to the PMA clock promotion to a Global Clock Network which introduces clock skew.

Resolution

To fix the timing violations, you can add the following QSF assignments to your design.

• set_instance_assignment -name GLOBAL_SIGNAL "PERIPHERY CLOCK" -to *altera_xcvr_10gbaser*av_rx_pma|clkdivrx
• set_instance_assignment -name GLOBAL_SIGNAL "PERIPHERY CLOCK" -to *altera_xcvr_10gbaser*av_tx_pma|clkdivtx

This problem will be fixed in a future version of the Quartus II software.