A customer of mine
ask me to design a PCI board starting from a sample board designed by "Oxford
semiconductor". As in many other PCI boards that I designed I followed the
PCI specs about traces lenghts ( 1.5 inches for interface data signals and 2.5
+- 0.1 inches for the clock ).
Checking the job I
discovered that the sample board from OS doesn't follows the PCI specs ( i.e
traces more long particularly for high address a26-a31...)
Investigating I
discovered the same situation in other boards like one from Conexant and
Brooktree ( this one designed by Praegitzer Design )
So my question
is:
Are those boards out
of specs or what are the really tollerances about lenghts?
best
regards
Bolis Bortolo
BB PCB Design
Via Gasparoli, 53
21012 Cassano Magnago ( VA ) - Italy
Tel. +39 0331 281457 Fax +39 0331 202794