Substractive Resource

Eric W. Biederman ebiederman at
Fri Dec 3 16:01:01 CET 2004

Li-Ta Lo <ollie at> writes:

> Eric,
> You explained substractive decoding to me long time ago but I really 
> forgot what it is. Could you tell me again ? Hoe do you determine if
> some resource of some device is substractive ? Form the data sheet ?

A subtractive bridge resource is a bridge resource that picks
up the unclaimed transactions and forwards them on.  In networking
the equivalent concept the default route.  A subtractive resource
is what picks up all of the traffic on a bus that does not have a
specific route to somewhere else.


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