Re: [hatari-devel] DMA sound and Falcon

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 12/09/2016 à 15:11, laurent.sallafranque@xxxxxxx a écrit :
> > I can fix this issue rather easily, I just need to take CpuFreqShift
> into account, but it won't fix the case where starting the same program
> at 16 Mhz sometimes gives correct sound and sometimes gives noisy sound.
>
>
> Yes, that's what I expect for now.
> I have more hope with the 68030 CPU improving (later) and memory access timings (later again).

Hi

I fixed falcon's crossbar to keep a constant sound rate when changing 
CPU freq at 8 MHz or 32 MHz.

What is interesting is that if you change cpu freq while playing a sound 
in "compatible STE dma mode" (for example between 16,8,16,8,...)
the sound will sometimes be noisy, then it will be clear again, or it 
will stay noisy all the time and so on.

This randomness really looks to me as if some variables are overflowing 
or are not correctly reset when computing the "steps" to convert from 
the requested Falcon sound freq to the host sound freq.

I will try to look at this when I got more spare time.

Nicolas