Path: utzoo!mnetor!uunet!husc6!purdue!decwrl!alverson
From: alverson@decwrl.dec.com (Robert Alverson)
Newsgroups: comp.arch
Subject: 80960 Register windows
Message-ID: <385@bacchus.DEC.COM>
Date: 20 Apr 88 17:46:10 GMT
References: <3358@omepd> <29454@linus.UUCP> <3392@omepd>
Reply-To: alverson@decwrl.UUCP (Robert Alverson)
Organization: Digital Equipment Corporation
Lines: 13
Keywords: 80960, RISC, embedded control

After hearing about the 80960 for the last few days, I still have a few
questions:

1. How are parameters passed into procedures?  In Berkeley's RISC, this
   was accomplished with overlapping windows.  What I have read seems to
   imply that the 80960 windows do not overlap.  How about procedure
   return values?

2. Just how much extra delay does register windows cost?  There may be extra
   decoding, or extra loading on lines, or extra time during call & ret (to
   switch register sets).  Nothing is free.

Bob