Re: [hatari-devel] Prefetch issue on 68000?

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 19/02/2013 10:32, Eero Tamminen a écrit :
> Hi,
>
> On tiistai 19 helmikuu 2013, Nicolas Pomarède wrote:
> > > Currently I wouldn't count so much on WinUAE core as its "cycle exact"
> > > cycles returned by Cycles_GetCounter(CYCLES_COUNTER_CPU) are more bogus
> > > (often there's zero diff from previous instruction) than the old UAE
> > > core provided ones.  :-/
> >
> > WinUAE's 68000 cycle exact mode is correct ; the fact that
> > Cycles_GetCounter (which is Hatari specific, not WinUAE) doesn't return
> > correct values sometimes is a problem in the Falcon's mode
> > implementation, not in WinUAE.
>
> What increments the CPU counter?  Any idea why it wouldn't be
> incremented on Falcon emulation for WinUAE core?

the cpu counter is "local" to each instruction and is reset when the 
instruction has been fully processed.
I know Laurent added some calls to get/set counter at some points to 
handle the number of cycles for the dsp, so it's probably related, but I 
don't know this part that much.

Nicolas