snakkewang的个人空间 https://blog.eetop.cn/174222 [收藏] [复制] [分享] [RSS]

空间首页 动态 记录 日志 相册 主题 分享 留言板 个人资料

日志

One way to solve local high congestion

已有 2344 次阅读| 2015-6-13 23:21 |个人分类:blog

Recently ,  i have worked on a very congested design.

The design have 5 metal layers.
As M1 is occupy by STD and M5 is occupy by Power Planning, only M2~M4 is for routing.
As M2-V, M3-H, M4-V, there is only one layer for Horizontal routing purpose .

The design is very congested, but after my research the design's shorts have be reduced from 200->0

The shorts that in the thin channel or something like that  is easy to fix, so it will not be discuss in this article.

I have list all the method that l used in the design ,  give the test result in my design and list my solution in the end.

1) Make sure you use most powerful effect during optimize 
      set placer_enable_high_effort_congestion true
      place_opt -area_reacovery -congestion 
      psynopt -area_recovery -area_effort high -congestion
Experience : After apply above option, the shorts have be reduced 10%, so it is not very effective for my design.

2) Floorpan 
    (1) Use Data Flow Analyze to analyze your floorplan.
    (2) Highlight the cell placement by Hierarchy.
    (3) Make sure all cells that in the same hierarchy be placement close enough.
         ( You can use deviation to evaluate it)
Experience : The congestion is very high sensitive to  the floorplan. Please make sure all cell group well in placement.

3)Power Plan
    Check whether all VIAs and Strip  of PG is friendly to the routing.
Experience :  No issue in my design.

4) Add partial placement blockage to the congested  area.
Experience : It has limited effect in my design. After i add the partial blockage, the new shorts happened in the boundary of blockage.

5) Add keep-out in special cell.
 Experience: It have limited effect in my design. After i add keep-out in two special cell (more pin cell), the congestion is better, but timing is bad. You will found large dis-placement  when you optimize the timing.

6)According to the statistic to add keep-out in the special area.
    (1)You can use script. to collect the cell info in the high congested area, then statistic it as "MAX CELL PIN" and "MAX TOTAL PIN". 
    (2)Base on the result , apply the keep-out to the special cell in that area.
    (3)ECO-placment and ECO routing 
    (4)Iteration more times to get better result.
Experience:
    It is very effective to my design and reduce shorts from 200-> 0. 

Please try it, if you have interested.

Thanks :) 


 

点赞

评论 (0 个评论)

facelist

您需要登录后才可以评论 登录 | 注册

  • 关注TA
  • 加好友
  • 联系TA
  • 0

    周排名
  • 0

    月排名
  • 0

    总排名
  • 0

    关注
  • 1

    粉丝
  • 0

    好友
  • 0

    获赞
  • 0

    评论
  • 1771

    访问数
关闭

站长推荐 上一条 /1 下一条

小黑屋| 手机版| 关于我们| 联系我们| 在线咨询| 隐私声明| EETOP 创芯网
( 京ICP备:10050787号 京公网安备:11010502037710 )

GMT+8, 2024-11-5 16:19 , Processed in 0.015408 second(s), 8 queries , Gzip On, Redis On.

eetop公众号 创芯大讲堂 创芯人才网
返回顶部