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VMots
Beginner
328 Views

multiple timing errors in 10GBASER phy core on clock nets xv_xcvr_10gbaser_nr_inst|ch[0].sv_xcvr_10gbaser_native_inst|native_inst|inst_sv_pma|tx_pma.sv_tx_pma_inst|tx_pma_insts[0].sv_tx_pma_ch_inst|tx_pma_ch.tx_cgb|pclk[1]

multiple timing errors in 10GBASER phy core on clock nets xv_xcvr_10gbaser_nr_inst|ch[0].sv_xcvr_10gbaser_native_inst|native_inst|inst_sv_pma|tx_pma.sv_tx_pma_inst|tx_pma_insts[0].sv_tx_pma_ch_inst|tx_pma_ch.tx_cgb|pclk[1]. Under Chip planner Quartus places soft fifo far from PCS, how to force it to make shorter paths?

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4 Replies
36 Views

Hi,

 

Fitter overconstraints are timing constraints that you adjust to overcome modeling inaccuracies, mis-correlation, or other deficiencies in logic optimization. You can overconstrain setup and hold paths in the Fitter to force more aggressive timing optimization of specific paths. 

 

You may refer to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug-qpp-timing-analyzer.p...

2.2.9. Using Fitter Overconstraints

 

 

Thanks.

VMots
Beginner
36 Views

Thanks for answer, I think overconstraining dramatically increase runtime. I was able to decrease TNS and meet additionally one constraint (from 2 remaining) by simple floorplan with logic lock and design partitioning features, and still going this way.

And if I can ask you - may be you can advise some document which describe methodology of using this features for Quartus Standard 18 or 19?

Thank you again

36 Views

Hi,

 

You may refer to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug-qps-timing-analyzer.p... Chapter 2.4.3 for Overconstrain in Standard edition.

 

Thanks

VMots
Beginner
36 Views

Issue solved by floorplaning. thanks

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