[En-Nut-Discussion] SRAM speed

[ethernut at dotaussie.com.au]

Hi Harald,

We'd be quite happy to help with the hardware design for that part of the
circuit, if you like. It certainly appears from your operating system that
you have put in massive amounts of work, and we have no real desire to have
to keep 'patching' the OS to meet a slightly different hardware
configuration. So if you were supporting our memory configuration, obviously
that would be great for both of us.

I actually expect delivery of some sample CPLD's tomorrow, with which I
intend on experimenting with some alternate memory interfacing systems, as
well as providing address decodes, etc. I will let you know how it goes.

Are you already committed to using a particular brand of CPLD chip? If so,
do you have any ideas on exactly which chip you want to use? The chips I
have been looking at are the Altera EPM3064/3128. (I think the 3032 would
end up too small, also there is a 100TQFP package for both the '64 and '128
which means ability for drop-in expansion)

Do you have any suggestions for other lines that you would like to pass
through the chip? I can imagine that SPI & I2C could be useful, for
interface to 3.3V chips. Are there any other ideas that you had that you
could suggest that we look at?

On the LAN chip, how do you go with the pricing of the SMC parts? I find
that (at least here in Australia) the SMC parts seem very expensive. Also,
what equipment do you use for hand-soldering the prototypes of these new
boards? The fine pitch surface mount chips look quite challenging (eg. LAN
chip)

Regards,

Alastair


-----Original Message-----
From: en-nut-discussion-admin at egnite.de
[mailto:en-nut-discussion-admin at egnite.de]On Behalf Of Harald Kipp
Sent: Thursday, 12 September 2002 6:49 PM
To: en-nut-discussion at egnite.de
Subject: RE: [En-Nut-Discussion] SRAM speed


Alastair,

After getting back to my old university books with
Karnaugh diagrams, Quine Mac Clusky expressions and
all this stuff, I soon realized, that simple logic
wouldn't help. The distributor told me, that nobody
uses GALs or PALs anymore and recommended a Cypress
Starter Kit. Somebody at egnite is currently playing
with Warp 6. That's the status - a bit simplified. :-)

Yes, I also find out that using a 5V tolerant chip
is the way to go. Another plan is to replace the
RTL8019AS with the SMCs LAN 91C111.

Everything is still open. Note, that I was forced
to get back to hardware, after I couldn't find
something like Ethernut two years ago, except Rabbit.
Rabbit is OK, but AVR and GNU looked much more
interesting.

I'm more addicted to software and will appreciate
any advice regarding the hardware.

Harald

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