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From: talesara@hpsrad.enet.dec.com (Hemendra Talesara HPS-AHSD (508) 467-5541 DTN:297  20-Sep-1989 1022)
To: "tel%computer-lab.cambridge.ac.uk@NSFnet-Relay.AC.UK"@decwrl.dec.com
Cc: TALESARA@decwrl.dec.com, "info-hol@clover.ucdavis.edu"@decwrl.dec.com
Subject: Looking for Specific Examples in Architecture Space

Please make suggestions on the following:
-----------------------------------------

Though,I have been working with formal methods, I have never ventured into
architecture space.  I would like to see specific examples of ambiguity,
incompleteness and inconsistencies in the specifications of any
architecure.  Also, one of the reasons one would like to do formal spec.
is the possibility of proofs of various properties.  What sort of
properties about the architecture one would like to prove.

Things like :

o Memory Mangement always correctly maps every address.

o Any time exception occurs what is the state of machine ? Can you always
recover from Page Faults ? Could machine ever get into a state that is
forbidden.

o When you are in user mode no clever set of sequences gets you into superviser
mode.


When you make suggestions like this, I would like to know from your
experience:  if one is really trying to address something that has been
problem or the exercise is academic in nature.  It would be nice to hear
any comments with specific examples that one might have encountered.

Thanks,

- Hemendra









