CPRI MegaCore Function Variations That Target an Arria V or a Stratix V Device Require Additional Constraints

Description

CPRI MegaCore function variations that target an Arria V or a Stratix V device require additional project settings to achieve timing closure.

The required constraints prevent timing violations associated with global reset signals in the affected variations. Note that Arria V variations configured to run at CPRI line rates higher than 3072 Mbps are affected by the erratum CPRI MegaCore Function Fails Timing in Arria V GX Devices at Line Rates Above 3072 Mbps.

Resolution

To avoid this issue, add the following constraints to the Quartus Settings File (.qsf) for your Quartus II project:

set_instance_assignment -name GLOBAL_SIGNAL OFF -to *local_reset

set_instance_assignment -name GLOBAL_SIGNAL OFF -to *rx_digitalreset_serdes_txclk_sync2

set_instance_assignment -name GLOBAL_SIGNAL OFF -to *rx_digitalreset_serdes_rxclk_sync2

set_instance_assignment -name GLOBAL_SIGNAL OFF -to "*cpri_sink:ilane_inst[*].cpri_sink_inst|comb~0"

set_instance_assignment -name GLOBAL_SIGNAL OFF -to "*cpri_src:ilane_inst[*].cpri_src_inst|comb~0"

This issue will be fixed in a future version of the CPRI MegaCore function.