[Opendispense] Large FPGAs

Harry McNally harrymc@ucc.gu.uwa.edu.au
Sun Aug 3 14:10:22 2003


On Sun, 3 Aug 2003 20:20:51 +0800 Nick Bannon <nick@ucc.gu.uwa.edu.au> wrote:

> On Sun, Aug 03, 2003 at 05:29:46PM +0800, Adrian Chadd wrote:
> > On Sat, Aug 02, 2003, Harry McNally wrote:
> > > After the discussion about comms alternatives, I'd like to find out
> [...]
> > How big an FPGA can you mount?
> > 
> > Say, an XCV1000E or two?
> 
> Those are the ones: Xilinx Virtex XCV1000E FG860, 8C ;
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4663&item=2545447811
> 
> Monumental overkill for our application, of course,

Not so :) Given the clock speed of our HC11 I have been thinking
of some cunning plans. I spoke to Nick about the idea of also
coding a serial port in the FPGA because the HC11 serial is being
used. With a device of this size we can design a DMA scheme that
cycle steals access to the static RAM on the daughter board and
just advises the micro when a SLIP packet has arrived and the
buffer address of the packet. This means a buffer allocator
needs to feed the SLIP state machine a stream of buffers so why
not include a buffer allocator state machine in the FPGA as well?
I think it would be possible. If we want to have some secure comms
to the accounting system we could build a hardware encryption
engine too to avoid loading the HC11. There are all sorts of
opportunities with a large FPGA limited by skill and imagination
mainly :-)

> but it goes to show
> that it can sometimes be affordable to get our hands on FPGAs with a
> million gates as opposed to 128... Of course, I have nil experience
> with working with any device of that type.

Well, me too, but the concept is the same FLW :) The difficulty is
where high speed circuits have timing contraints that depend on layout.
We don't need to run fast, we just need room for logic so I think we
could stumble on a solution.

I need to look at the free version of the MAXplus tools from Altera 
to see if it supports these devices. I'd like to use tools that are
free so other can play without needing the $$$ toolset.

comes back .. ok I've just looked at the MAXplus 10.2 Baseline I have
on a PC here and it doesn't look like it is supported in this version.
It's been a while since I updated so there may be a more recent
version with support. What are MUGWA using for development? Are there
GPL tools for these sorts of densities? 

Harry

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