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Visitor
Visitor
239 次查看
注册日期: ‎12-02-2019

将工程从VIVADO 2017.4移植到VIVADO2020.1,timing急剧恶化,请问什么原因?

Device : xcku15pffve1517-2,资源70%。

在2017.4的时候,我们wns绝大多数都会小于-0.1ns。

但是移植到2020.1,wns大部分都会大于-0.4ns,跑到-0.8ns,-0.9ns也很常见,有时还会是-1ns,甚至是-3ns,-8ns。

这两个版本我们只升级了IP。

请问为什么差别这么大?

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Visitor
Visitor
198 次查看
注册日期: ‎12-02-2019

比如到了这一步,为什么最终的WNS=-0.329 比最后一步优化后的WNS = -0.185还要差?这个算法是不是有问题?

Phase 12.2 Critical Path Optimization
INFO: [Physopt 32-668] Current Timing Summary | WNS=-0.433 | TNS=-1089.364 | WHS=0.010 | THS=0.000 |
INFO: [Physopt 32-952] Improved path group WNS = -0.407. Path group: txoutclk_out[0]_1. Processed net: inst_…………

……………………………………
INFO: [Physopt 32-952] Improved path group WNS = -0.186. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-952] Improved path group WNS = -0.186. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-952] Improved path group WNS = -0.185. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-953] Path group WNS did not improve. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-953] Path group WNS did not improve. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-953] Path group WNS did not improve. Path group: clk_out1. Processed net: inst_…………
INFO: [Physopt 32-668] Current Timing Summary | WNS=-0.329 | TNS=-1051.538 | WHS=0.003 | THS=0.000 |
Phase 12.2 Critical Path Optimization | Checksum: 1a2a94c96

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Moderator
Moderator
132 次查看
注册日期: ‎11-05-2010

有查看时序报告,查过时序不理想的原因吗?会不会是约束不同引入的问题?

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