| Finally tracked down the def'n of hidden. Was a bit surprised that it was
not listed in the VMEbus Handbook referenced in .0.
However, extracted from notes - courtesy Graham Crosbie:
VME bus requester:
fairness : if fair, the bus requester refrains from requesting the bus a
second time until there are no other bus requests pending. [According
to the VMEbus handbook, this gives equal priority to all masters. These
requesters can be used when many masters need fixed bandwidth and are
often used with single level arbiters. Further, it states for the FAIR
requester to work properly, all bus grant levels with multiple masters should
have FAIR requesters. If one or more modules don't have one, it should be
verified that the bandwidth used by the non-FAIR module is less than that
used by the FAIR requester(s). /ab]
Hidden : if hidden, the requester allows all bus requesters to arbitrate for
the bus while a bus data transfer is in progress, thus increasing bus
throughput. If hidden mode is to be used, all requesters on the bus must
support hidden mode.
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