Hi, can anybody tell me how to get the total gate count approximation from Logic Elements (LEs) in Altera Stratix and APEX device??? Thank you very much.
- posted
19 years ago
Hi, can anybody tell me how to get the total gate count approximation from Logic Elements (LEs) in Altera Stratix and APEX device??? Thank you very much.
The gate count is a random number generated by marketing used to 'prove' one FPGA is better than another. Its usually based upon the number of and gates you can implement multiplied by a fudge factor.
Have a look at the internal macrocell structure. It is different depending on the family. It basically is a Flipflop with some logic in front. The compiler converts your wishes to connections. Depending on your preference speed may be the focus or size. The resulting connections leave some unused gates. The rough LE-to-gatecount estimate are ballpark figures and just tell you about the order. Make sure not to plan with an FPGA that is too small. You best do a design with the supplied tools and let the tool choose a chip for your. Then have a look at the unused gates and think about future wishes and such.
Rene
-- Ing.Buero R.Tschaggelar - http://www.ibrtses.com & commercial newsgroups - http://www.talkto.net Jasmine Hau wrote: > Hi, can anybody tell me how to get the total gate count approximation > from Logic Elements (LEs) in Altera Stratix and APEX device??? Thank > you very much.
Check out AN 110: Gate Counting Methodology for APEX 20K Devices -
LE's from APEX roughly compare to Stratix LE's if LUT's and Registers is what you need.
K.R. Karl
Hi Jasmine,
maybe you could have a look at a data sheet of Altera Stratix devices where the build up of such a Logic Element is explained. I guess there you should be able to find the number of gates per LE.
Rgds
André
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