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 oferst
Visitor
2,219 Views
Registered: ‎05-09-2017

Spartan 3AN utilization report contradiction in ISE 14.3

Hello, new here!

I need some help.
I tried implementing my design for xc3s700an using ISE 14.3.
I had a hard time with the PAR process, running out of resources.
Anyway, going over the PAR report I found something wierd.
xc3s700an has 5888 slices, half of them are SLICEM and half are SLICEL.
I almost ran out of slices but the report shows 5659 out of 5888 slices are used while only 475 out of SLICEMs are used. How can that be?

Thanks for are helpers!
0 Kudos
2 Replies
Visitor oferst
Visitor
2,214 Views
Registered: ‎05-09-2017

Re: Spartan 3AN utilization report contradiction in ISE 14.3

I meant 475 out of 2944 SLICEMs of course. Too bad I can't edit the first post.
0 Kudos
Instructor
Instructor
2,179 Views
Registered: ‎08-14-2007

Re: Spartan 3AN utilization report contradiction in ISE 14.3

The utilization report for SLICEM only indicates the number of slices that use the extra functionality of the SLICEM (distributed RAM, SRL...) and not the slices that could be implemented in SLICEL if enough were available.  This number indicates that you have the ability to use more SLICEM logic if necessary.  For example, if you have a lot of pipeline registers in the design you might be able to code those registers without reset.  That would allow them to be placed in SRL instead of (or in addition to) fabric flops, possibly saving total slices.

-- Gabor
0 Kudos