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Article #51564680x0 clr instruction
From: D. Erway
Date: Wed, 05 May 1993 00:13
Date: Wed, 05 May 1993 00:13
11 lines
1248 bytes
1248 bytes
The original 68000 clr instruction would do a read before write. This lead to headaches in device driver code, where reading an address does something. Does anyone know if the latter members of this family continue to do this, or if they gave up the stupid useless bus cycle? I am specifically interested in 68030. The reason I ask this group is that I am changing over compilers, and my old compiler had a switch to disable it using the clr instruction. I can find no such switch in gcc 2.3.3 Perhaps it no longer matters though... -Don
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 11318c,52499d5dab982a68,start X-Google-Attributes: gid11318c,public X-Google-ArrivalTime: 1993-05-04 17:44:15 PST Path: arc1-ca.pugleaf.net!gmd.de!Germany.EU.net!mcsun!uknet!doc.ic.ac.uk!agate!howland.reston.ans.net!usc!news.service.uci.edu!ucivax!news.claremont.edu!nntp-server.caltech.edu!derway From: derway@cco.caltech.edu (D. Erway) Newsgroups: gnu.gcc.help Subject: 680x0 clr instruction Date: 5 May 1993 00:13:04 GMT Organization: California Institute of Technology, Pasadena Lines: 14 Distribution: gnu Message-ID: <1s70qhINNruc@gap.caltech.edu> NNTP-Posting-Host: alumni.caltech.edu Summary: 680x0 clr instruction read before write?