Lpc2000

> Two questions:
> 
> 1) Does "leading 12 bits" mean the first 12 bits transmitted? These
are the 
> most significant bits in the message Id right?
Yes thats what we found, and probably zthat the reason why the bug
only happens to occur with 29 Bit Identifiers. 

> 2) So does this mean that if there is a difference in this area,
then the 
> arbitration will be OK?
In our tests, we did not get this faults when there was a difference
in this area (first 12 Bits).
> 
 
> This will likely break many/most J1939 or SAE11785 systems which
will often 
> only have differences in the last (lsb) 16 bits.

That's right and that really makes the can controller useless in such
kind of applications.

When we reported this problem to Philips the german Philips FAE told
us that there was a known problem in this area, but their report did
not mention corrupted messages but totally lost messages.
May be, their setup had an accepptance filter setting which catched
the corrupted frames.
Nevertheless i found it very disappointing, that Philips obviously
does not report all know problems to the customers.
By the way the actual errata sheet on the web still does not mention 
this kind of problem.