Re: standard loads on 66 MHz PCI

> I wonder if this is really a non-issue? Does the somewhat "unusual" passage in
> the PCI spec about Tval loading necessarily mean that the vendor datasheet for
> that component must use the same loads? Couldn't the vendor specify a
> "traditional" standard load in the datasheet and still comply with PCI?

How do you demonstrate compliance in all corner cases with a
single load datasheet? Especially if that single load is not
_any_ of those given in the design spec? Any device which
complies in one corner case may comply in the others, or it
may not. PCI takes the right approach in explicitly specifying
the corner cases. It's up to customers to demand appropriate
data sheets and models.

Is it feasible to expand the IBIS model spec and build enough
intelligence into the simulators so that together they can
automatically simulate all the corner cases in a given design?
That would be required to meet the logic designers' expectation
for a plug-and-chug solution. (Most SPICEs have monte carlo
capabilities for such work; they require manual intervention
to set parameter limits et cetera, but at least they don't
require a different model for each loading case. With a model
consisting of multiple sets of I-V and V-T curves, one per
loading case, there's more scope for error: knowing that the
set for one case is correct does not tell the user whether the
other sets are correct.)
Received on Tue Nov 10 08:07:47 1998