Re: Homebrew STG card Update

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Paul Corner wrote:

> Jon - as a side note, Lattice sent me a CD with details of a 'free' PCI design.
> Subject to signing a NDA. Might be worth a closer look for anyone contemplating
> that route. Having looked at the FPGA chips, most of the logic could be burnt
> into just one chip. The real disadvantage of this is the pin counts on the
> chips. 178 pin QFP or worse, BGA packages ( surface mounted PGA's) and the pin
> count goes up with the gate density.
>
> > > > Another possibility is to encode all the logic, both ISA interface,
> > > > digital I/O, and the encoder counters into a programmable gate
> > > > array device.  Then, the entire board would consist of one big
> > > > chip, like the Xilinx XC95160 and one or two A/D and D/A
> > > > chips.

Yes, and the amazing thing is that these chips go for about $35 in single
quantity!  The advantage with the Xilinx is it doesn't need an outboard
serial ROM, and can be reprogrammed almost indefinitely.  The programmer
contains one interface driver chip, to boost parallel port signals to
good CMOS levels.

> > > He's right about that... plus with canned PCI interface libraries
> > > (using these chips is like writing C code) interfacing to that more
> > > popular bus would no longer be unrealistic.
> >
> > I'm still looking for a cheap PCI library.  One that I know of is $9000.

Yes, if anyone knows about a simple PCI interface code that is
'open source' I'd sure like to know about it.  We don't need DMA, 32-bit
burst transfers, we can probably even live without interrupts.

Jon