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manivannanrm
Joined: 23 May 2006
Posts: 24
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 23 Aug 2006 5:22 Logic Synthesis & Physical synthesis ? |
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Can anybody explain Logic synthesis and physical synthesis ?
And its difference ?
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stormwolf
Joined: 03 Jan 2004
Posts: 114
Helped: 11
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| 23 Aug 2006 9:00 Logic Synthesis & Physical synthesis ? |
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Logic synthesis just translate RTL to netlist , and some physcial information is not accurate (such as wire load model, cell place).
phsysical synthesis can get some physcial information from layout, it physcial information is accurate than logic synthesis. And some physcial synthesis not only translate RTL to netlist , it can translate RTL to Layout.
And usally some logic synthesis tools have the command to read some physical information. such as "read_spef" in dc to read floorplan . But how to use it , i don't clearly.
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funzero
Joined: 19 Nov 2004
Posts: 203
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| 23 Aug 2006 12:02 Re: Logic Synthesis & Physical synthesis ? |
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logic synthesis just do translating and mapping .
but physical synthesis do floor planning . and trial layout . It will
help physical designer to determine the blocks relationship . and give a good timing result .
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manivannanrm
Joined: 23 May 2006
Posts: 24
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| 23 Aug 2006 13:08 Re: Logic Synthesis & Physical synthesis ? |
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tnz for ur answers.
Can I say physcial synthesis as complete backend (starts from floorplanning to routing).
The logic synthezed file format will be .v ,what abt phys.synt. file format?
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beta0
Joined: 24 Nov 2003
Posts: 117
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| 23 Aug 2006 16:21 Re: Logic Synthesis & Physical synthesis ? |
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| manivannanrm wrote: |
tnz for ur answers.
Can I say physcial synthesis as complete backend (starts from floorplanning to routing).
The logic synthezed file format will be .v ,what abt phys.synt. file format? |
No, physcial synthesis is start from your RTL code
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rajesh9999
Joined: 19 Oct 2005
Posts: 44
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| 23 Aug 2006 21:23 Re: Logic Synthesis & Physical synthesis ? |
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"Can I say physcial synthesis as complete backend (starts from floorplanning to routing).
The logic synthezed file format will be .v ,what abt phys.synt. file format? "
The equivalent file for physical synthesis is DEF. DEF is an industry format that encapsulates physical information. At any given stage if you write out .v and .def you will have saved the database and can start from the same point again by reading the .v and .def.
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sarath51
Joined: 11 Dec 2002
Posts: 143
Helped: 7
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| 24 Aug 2006 0:28 Re: Logic Synthesis & Physical synthesis ? |
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| normal synthesis has wire load models where are in Physocal synthesis wireloads are excluded and physical information ( like floor plan location etc ) are fed in . In addition to normal db file libraries with physocal information ( pdb or milkway ) is read in the tool for optomizatiomn. The end result is give rialisitic view of timing
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manivannanrm
Joined: 23 May 2006
Posts: 24
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| 25 Aug 2006 14:53 Re: Logic Synthesis & Physical synthesis ? |
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The answers were helpfull.
But still I have one doubt where does the term phy. synthesis will be used I feel that from fplanning to routing.Please correct me if i am wrong.
Previously there is an answer as it starts from rtl code.
tnx in advance
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elec-eng
Joined: 16 Nov 2006
Posts: 236
Helped: 14
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| 11 Jun 2008 19:31 Logic Synthesis & Physical synthesis ? |
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| http://www.soccentral.com/results.asp?CatID=488&EntryID=16959
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naveen_zs
Joined: 10 Nov 2008
Posts: 16
Helped: 1
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| 11 Nov 2008 8:45 Re: Logic Synthesis & Physical synthesis ? |
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hi manivannanrm
As answered above physical synthesis will start from rtl , the other option is you can take the logical synthesized netlist as a input and you can synthesis with power models (for all cells) in place of wlm (wire load model)
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nine8
Joined: 18 Sep 2007
Posts: 36
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| 12 Nov 2008 14:50 Logic Synthesis & Physical synthesis ? |
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physical syn will do the virtual floorplan first, and then i can calculate the wire delay vaule which is near to the real floorplan, so the resule it's very
Added after 1 minutes:
physical syn will do the virtual floorplan first, and then i can calculate the wire delay vaule which is near to the real floorplan, so the resule it's very
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