UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

cancel
Showing results for 
Search instead for 
Did you mean: 
Visitor nithinks1
Visitor
7,613 Views
Registered: ‎08-07-2015

Synthesis option fast_synthesis resdution in LUT

Hello,

i am working on Virtex-7 FPGA xc7v2000tflg1925

   I am using synthesis option fast_synthesis

 

When I set thios otion to "1", after synthesis I get LUT Utilization to 89%

 

When i set this otion to "0", after synthesis I get LUT utilization reduced to 69%

 

How is it possible to get so much Reduction??

 

Thanks,

Nithin

0 Kudos
3 Replies
Scholar pratham
Scholar
7,610 Views
Registered: ‎06-05-2013

Re: Synthesis option fast_synthesis resdution in LUT

@nithinks1 Synplify forum would be correct to answer this question

 

What i could suggests here is fast_synthsis doesnt do advance optimization which normal synthsis does inorder to reduce the run time hence resulting larger utilization.

-Pratham

----------------------------------------------------------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.

Give Kudos to a post which you think is helpful and reply oriented.
----------------------------------------------------------------------------------------------
0 Kudos
Xilinx Employee
Xilinx Employee
7,592 Views
Registered: ‎10-24-2013

Re: Synthesis option fast_synthesis resdution in LUT

Hi,


To my knowledge this option optimizes the design for better synthesis run time at the cost of area/utilization numbers.

 

Its design choice to have a trade-off between area & performance.

 

As suggested by pratham, contact synopsys for more details.

Thanks,Vijay
--------------------------------------------------------------------------------------------
Please mark the post as an answer "Accept as solution" in case it helped resolve your query.
Give kudos in case a post in case it guided to the solution.
0 Kudos
Moderator
Moderator
7,589 Views
Registered: ‎07-21-2014

Re: Synthesis option fast_synthesis resdution in LUT

@nithinks1

 

When you select run time as priority for a particular run then tool will not try much to enhance the performance as compare to other runs when performance is set as priority. As per my understanding, tool will try to deliver the best results with reduced overall run time.

 

Thanks,
Anusheel
-----------------------------------------------------------------------------------------------
Search for documents/answer records related to your device and tool before posting query on forums.
Search related forums and make sure your query is not repeated.

Please mark the post as an answer "Accept as solution" in case it helps to resolve your query.
Helpful answer -> Give Kudos
-----------------------------------------------------------------------------------------------

0 Kudos