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Message
From: mn_engineer@y...<mn_engineer@y...>
Date: Sat Feb 12 19:14:24 CET 2005
Subject: [pci] Opencore PCI in Altera Cyclone - SERR update
Page 59 of AN-315 talks about "programmable ground". I believe this is
just talking about what your unused, unconnected IO pins are set to. In
high speed design you should never leave them tri-stated. So make sure
all unused, unconnected IO are set to outputs, driving GND.
You mentioned the PCI interface, the requirements are:
Max length for 32-bit interface signals = 1.5"
Max length for additional 64-bit interface signals = 2.0"
PCI CLK length = 2.5" +/- 0.1".
Note that the PCI CLK length is a specific value, and not a maximum.
----- Original Message -----
From: Andrés Trapanotto<andres_t@i...>
To:
Date: Fri Jan 21 18:25:18 CET 2005
Subject: [pci] Opencore PCI in Altera Cyclone - SERR update
> Hi Dave!
>
> Dave Warren escribió:
>
> >I added extra capacitors in order to improve the power rails by
> the Cyclone
> >EP1C12Q240C8 FPGA. Now on the scope the 1.5V and 3.3V looks
> very clean.
> >However I still get the SERR errors. This is dispite the
> Quartus reporting
> >that it can meet timing for 33Mhz PCI.
> >
> >I am being forced to consider buying a commercial core. One
> thing I have
> >discovered is that they are all qualified for specific pin
> outs, it seems
> >they only guarentee they work if you use these. I suggest that
> anyone
> >looking to do PCI lifts the pin out from Altera. What I noticed
> that they
> >don't use every I/O in a bank (with the pin out for the 240QFP
> 5 were
> >spare), unused I/O's are grounded. Maybe they have to do
> something like that
> >to make it work.
> >
> >
> Haven't you grounded unused I/ O's?
> Try setting every unused I/O as input and ground them.
> Good Luck!
> --
> Técnico Andrés Trapanotto
> INSTITUTO NACIONAL DE TECNOLOGÍA INDUSTRIAL
> Centro de Investigación Telecomunicaciones, Electrónica e
> Informática
> Teléfono (54 11) 4724 6300 Interno 6362
> andres_t@i...
> ___________________________________________
> 0800 444 4004 | www.inti.gov.ar
>
>
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