Re: FPGA for PCI based servo control board

[John Sheahan <jrsheahan-at-optushome.com.au>]

On Tue, Apr 01, 2003 at 01:52:57AM -0500, Jon Elson wrote:
> 
> 
> 
> ERIC KELLER wrote:
> 
> >I looked at a lot of fpgas to use for PCI interfacing.  I came down to the
> >notion that only the Xilinx Spartan II made sense.
> >The Spartan II has 3.3 and 5 v i/o, and thus is 5v pci compatible.
> >
> That is NOT true 5 V I/O.  It is 5V TOLERANT I/O.  If you want to pull 
> up above
> 3 V, you need low-value pull-up resistors external to the chip.  If you 
> need really fast
> positive-going transitions to +5 V, you can't get them.
> 
> Jon
> 


true - but 5v pci only needs to be 5v tolerant. 
driving 3v3 is in specification. 

is there much 5v PCI any more?
john