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asic:pnr:start [2023/11/23 12:06]
rajit created 		asic:pnr:start [2023/11/23 12:13] (current)
rajit
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-===== Placement and routing =====+====== Placement and Routing ======
  
-Once the routed cell library ''.rect'' files are ready, using the same script as above will create a layout problem for place and route that includes the correct LEF for the cells.+To use the place and route flow, we need a completed [[asic:cells:start|cell library]]. The ''.rect'' files for the completed cell library (that include the full cell geometry, including wiring) with the configuration variables pointing to the cell library path. 
 + 
 +Once the routed cell library ''.rect'' files are ready, using the same ''interact'' script described in the cell mapping step will create a layout problem for place and route that includes the correct LEF for the cells. The script is repeated here: 
 + 
 +<code> 
 +$ interact -ref=1 -Tsky130l  
 +interact> act:read "out.act" 
 +interact> act:merge "cells.act" 
 +interact> act:expand 
 +interact> act:top sdt_triple 
 +interact> ckt:cell-map 
 +interact> load-scm "phydb.scm" 
 +interact> phydb:create 1.8 1  "output.lef" 
 +interact> 
 +</code> 
 + 
 +Running this with the correct ''.rect'' files will ensure that the generated LEF will include correct pin locations, routing obstacles, etc. 
 +===== Placement  =====
  
 The next step is to run the [[https://ieeexplore.ieee.org/document/9256795|placement engine]] called ''dali''. To do so, continue with the following ''interact'' commands: The next step is to run the [[https://ieeexplore.ieee.org/document/9256795|placement engine]] called ''dali''. To do so, continue with the following ''interact'' commands:
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 </code> </code>
  
-This flow corresponds to a gridded placement flow. For gridded cells, the power buses are run after placement. To run this special power bus router, use the following commands:+This flow corresponds to a gridded placement flow.  
 + 
 +===== Power routing ===== 
 + 
 +For gridded cells, the power buses are run after placement. To run this special power bus router, use the following commands:
 <code> <code>
 interact> pwroute:init 3 interact> pwroute:init 3
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 </code> </code>
 Here we turn off reinforcements, as the technology does not have many metal layers. For a more modern process, the power router is capable of adding horizontal and vertical reinforcements of the power grid as well. Here we turn off reinforcements, as the technology does not have many metal layers. For a more modern process, the power router is capable of adding horizontal and vertical reinforcements of the power grid as well.
 +
 +===== Global routing =====
  
 Finally, we can run the global router called ''sproute'' as follows: Finally, we can run the global router called ''sproute'' as follows:
asic/pnr/start.1700759196.txt.gz · Last modified: 2023/11/23 12:06 by rajit
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