how to choose device properties in ise8.2i

[pooja_khubbar]

Dear all..

am using ise 8.2i and the device properties i choose are
• Device Family: Spartan3
• Device: xc3s200E
• Package: FG320
• Speed Grade: -5
• Synthesis Tool: XST (VHDL/Verilog)
• Simulator: ISE Simulator (VHDL/Verilog)
• Preferred Language: verilog

because these properties are mentioned in manual...but i dont know the meaning of these properties and if these are standard then why other options are given... like if i choose speed grade -4 instead of -5 what will b its effect...please provide me some links that make the doubt clear...

 

[alexan_e]

There are devices that are produced in different packages with different pin count so a model is not enough, that's why there is also a package setting.
There are also speed grades that can work faster than others, this is printed in the chip case and is explained in the datasheet.
The synthesis too can be the XST which is the internal xilinx one or you can use an external commercial one.

If you change the grade then the reported net delays and timings will be reported wrong and also if you do a post fit simulation you will get wrong results.

Check page 8
https://www.xilinx.com/support/documentation/data_sheets/ds099.pdf

Alex