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Atari demoscene BBS
| Re: DSP cycles |
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Posted by: mikro
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Feb,25.2010-18:10
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I can check at home but from top of my head -- there's simple rule, DSP is able to handle one external access + all internal accesses in one bus cycle, i.e.:
mpy x0,y0,a
mpy x0,y0,a x:(r0)+,b
mpy x0,y0,a x:(r0)+,b x:(r4)+,b
still take the same amount of time if x/y are internal (p doesn't matter here).
if one of p/x/y is external, for every next external access add +1 bus cycle, so for extreme case where p, x and y are all external, it will cost you 3 bus cycles, if none of them is external, it will still cost you one bus cycle.
about the length / duration of bus cycle, I have no idea, probably +1 is OK for hatari.
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Topic
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Posted by
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Date
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DSP cycles
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Sallafranque
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Feb,23.2010-00:56
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Re: DSP cycles
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mikro
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Feb,23.2010-12:40
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Re: DSP cycles
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Sallafranque
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Feb,24.2010-02:49
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Re: DSP cycles
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Sallafranque
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Feb,24.2010-02:49
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Re: DSP cycles
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mikro
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Feb,24.2010-11:50
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Re: DSP cycles
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Sallafranque
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Feb,24.2010-13:43
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Re: DSP cycles
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Chuck/Dune
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Feb,24.2010-13:56
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Re: DSP cycles
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Sallafranque
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Feb,24.2010-14:06
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Re: DSP cycles
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mikro
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Feb,25.2010-00:54
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Re: DSP cycles
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Sallafranque
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Feb,25.2010-14:14
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Re: DSP cycles
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mikro
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Feb,25.2010-18:10
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Re: DSP cycles
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Patrice Mandin
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Feb,25.2010-19:38
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Re: DSP cycles
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Sallafranque
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Feb,27.2010-11:13
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What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
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