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- Path: solaris.cc.vt.edu!usenet
- From: dornbush@vt.edu (Andrew Dornbusch)
- Newsgroups: comp.sys.m68k
- Subject: Re: Spurious Interupts on 68360
- Date: Sun, 17 Mar 1996 23:54:17 GMT
- Organization: Virginia Tech, Blacksburg, Virginia
- Message-ID: <4ihu1q$ala@solaris.cc.vt.edu>
- References: <4ia48q$lnj@python.microcom.com>
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-
- >We're getting spurious Interupts on our 68360. As far as I can tell from the
- >manual, this is not caused by anything in my code, but rather by something
- >going wrong inside the 68360. Is this correct?
-
- My experience with spurious interrupts occured on a '332, but I
- believe that the causes are likely the same. A spurious interrupt
- occurs when you have an external (IRQ1-7) interrupt input but do not
- have an interrupt acknowledge set up. The CPU32 MUST have an INTACK.
- It can either come from your external device, or be generated by an
- unused chip select output. If the CPU32 gets an interrupt input but
- not an interrupt acknowledge, it assumes that the interrupt was
- errant, hence the term 'spurious'. If your external device cannot
- supply the INTACK, consult your '360 manual in the SIM section under
- 'Chip-Select Operation'; that will show you how to generate it
- internally.
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