{"id":4193,"date":"2018-10-03T05:41:05","date_gmt":"2018-10-03T05:41:05","guid":{"rendered":"https:\/\/support.plunify.com\/en\/?p=4193"},"modified":"2018-10-04T05:38:19","modified_gmt":"2018-10-04T05:38:19","slug":"how-to-get-53-improvement-in-wns-from-running-placement-seeds-in-vivado","status":"publish","type":"post","link":"https:\/\/support.plunify.com\/en\/2018\/10\/03\/how-to-get-53-improvement-in-wns-from-running-placement-seeds-in-vivado\/","title":{"rendered":"How to get 53% improvement in WNS from running “Placement Seeds” in Vivado"},"content":{"rendered":"

At the beginning of 2017, we published an article about running \"seeds\" in Vivado -\u00a0Who Says You Can\u2019t Use Random Seeds In Vivado?<\/a>\u00a0 Although Vivado does not support the \"placement cost table\" feature, InTime has a feature called \"Placement Exploration\", which enables similar behavior without any impact on functionality. In this post, we are going to showcase results from customer designs, understand the impact of this placement recipe and how it can help you.<\/p>\n

What is \"Placement Exploration\" recipe?<\/h2>\n

To recap for our users and for new readers, Placement Exploration is a strategy to randomize non-critical register location. This enables Vivado to explore\u00a0more opportunities, apply difference placement and routing calculations to give different results\u00a0without changing the design functionality.<\/p>\n

How this works<\/h2>\n

This recipe requires the design to have some non-critical cells (cells have met timing path) and some unused slices in the targeted device. The more unused slices in the design, the more combinations of the run can be created, hence increase the randomization and possibilities of getting better results.<\/p>\n

If the requirements are not fulfilled, user will get following error when running the recipe:<\/p>\n

\"\"<\/p>\n

In this case, you might need to review the design to see if there are no false path (for the InTime\u00a0version before 2.2.1) or a low number of available free slice for the device. If it is due to no false path, you might want to check whether false path can be set for the design.\u00a0 To understand how to use this recipe, please refer to the application note here<\/a>.<\/p>\n

The Yummy Parts: Results from Real Designs<\/h2>\n

Project 1<\/h3>\n