On Sun, Oct 29, 2006 at 12:14:37PM +0100, Attila Kinali wrote:
> On Sun, 15 Oct 2006 18:24:24 -0400
> Jack Carroll <[EMAIL PROTECTED]> wrote:
>
> > On Sun, Oct 15, 2006 at 02:37:51PM -0400, Timothy Miller wrote:
> > > What matters for TRV10 is having the physical signals.
> >
> > Are you speaking of output signals at actual output voltage and
> > impedance, or only their logical representations?
>
> If you have the logical signals, then it's no problem at all
> to provide them at the appropriate voltage levels, if you
> are doing an ASIC anyways. Just choose the library elements
> for the pins/pads accordingly.
>
> > It seems to me that once
> > the TRV10 is available, it would be possible to spawn a variety of OGC
> > boards
> > and non-Traversal boards that implement different electrical interfaces, or
> > external accessories that convert TRV10 logic outputs into electrical
> > signals meeting different standards.
>
> I doubt that many people would like to do that. If possible,
> then TRV10 should provide as many electrical standards as
> possible, because each additional chip means additional cost.
> (more just then the price of the chip.. a lot more)
> And people like to avoid that.
>
> > Many computer cases have blank slots
> > where there is no card socket; that's a place where a rear panel with an
> > unusual connector could be mounted. Imagine, for just one example, LVDS
> > signals leaving an OGC accessory connector, going up a 3" ribbon cable to an
> > accessory board with bleeding-edge DACs and a 13W3 connector. The nice
> > thing about it is that we don't have to deal seriously with such
> > possibilities until the need appears.
>
> Actualy, that's a nice idea. The problem with this is, taht it
> would require an additonal connector on the board which is specified
> for high frequency signals. Those connectors tend to be very expensive
> unless you use one that is an industry standard (maybe scsi?).
> But even then, it will increase the card cost and thus make its
> position on the market more difficult.
Well, that gets us back to the idea that there can be more than one
board-level product that uses the TRV10. It allows people who need special
features to order them, without burdening everybody else with the parts
cost. Even if the signals for a variety of interfaces are implemented on
the ASIC at correct voltage levels and impedances, a plain-vanilla card
probably couldn't provide sites for all the required connectors. So some
external interfaces might be implemented on alternate PCB layouts, and
others might be provided on plug-in accessories. TRV10 could become the
central building block for a large and long-lived family of products.
Samtec makes some very small connectors with internal ground planes
suitable for large numbers of transmission lines, both single-ended and
balanced. Samtec is on the expensive side, but not compared to the cost of
a big IC like the TRV10.
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