Question about Spartan 3E starter kit

Hi there - I'm very new to FPGAs and so I'm probably doing many dumb
things. I recently got a Spartan 3E Starter Kit (http://
www.digilentinc.com/Products/Detail.cfm?Prod=S3EBOARD&Nav1=Products&Nav2=Programmable).
I followed the guide shown here: http://www.fpga4fun.com/ISEQuickStart.html
to make a new project. When selecting the device I said:

Product Category: All
Family: Spartan 3E
Device: XC3S500E
Package: FG320
Speed: -4

I wasn't sure about the speedgrade - but I googled around and found
some other people had used -4 for that option on similar boards. Is
that the correct choice? How would I figure that out? Also, what
exactly does the speedgrade mean? The help file wasn't very verbose
about it.

Thanks!

-Michael

Michael wrote:
>
> I wasn't sure about the speedgrade - but I googled around and found
> some other people had used -4 for that option on similar boards. Is
> that the correct choice? How would I figure that out? Also, what
> exactly does the speedgrade mean? The help file wasn't very verbose
> about it.
>
> Thanks!
>
> -Michael

Hi Michael,
It's written on the chip. You'll see 4C somewhere, I expect. This is 
speedgrade 4, commercial temperature range. The speedgrade is used to 
guarantee the speed of the innards of the device. Read the datasheet, and 
look for the 'switching characteristics' section.
HTH., Syms. 

On Apr 13, 6:25=A0pm, "Symon" <symon_bre...@hotmail.com> wrote:
> Michael wrote:
>
> > I wasn't sure about the speedgrade - but I googled around and found
> > some other people had used -4 for that option on similar boards. Is
> > that the correct choice? How would I figure that out? Also, what
> > exactly does the speedgrade mean? The help file wasn't very verbose
> > about it.
>
> > Thanks!
>
> > -Michael
>
> Hi Michael,
> It's written on the chip. You'll see 4C somewhere, I expect. This is
> speedgrade 4, commercial temperature range. The speedgrade is used to
> guarantee the speed of the innards of the device. Read the datasheet, and
> look for the 'switching characteristics' section.
> HTH., Syms.

Hi Symon - you're right - 4C is printed on the chip. Thanks for the
help!

I've just run into one other problem: I tried changing my code around
a bit - I changed one of the output names and added a new output. I
then went to assign package pins and assigned pins to the two new
outputs. I then tried to generate a programming file. This gave me an
error about the .ucf containing a reference to the old name of the
output whose name I changed. I couldn't figure out why that would
happen though. When I did the "assign package pins" shouldn't it have
fixed that? I mean - when I assign package pins doesn't that create
the .UCF file? Eventually I clicked on "Edit Constraints (text)" and
removed the line (which was the very first line, oddly enough, above
where it says "#PACE: Start of Constraints generated by PACE") that
referenced the old output name. That fixed the problem and I was able
to generate the programming file and program it just fine. But what
was the proper way to deal with that? I'm very new to all this so I
want to make sure I don't get into any bad habits.

Thanks!

-Michael