Re: [hatari-devel] No sound in the Pacemaker Demo

[David Savinkoff <dsavnkff@xxxxxxxxx>]

Note that the data and mask are serially clocked and shifted out
to form the three wire interface; data, data_enable, and clock.

----- David Savinkoff wrote:
> ----- Nicolas Pomarède wrote:
> > Le 29/05/2014 20:00, Jerome Vernet a écrit :
> > > On 29/05/14 16:28, Eero Tamminen wrote:
> > 
> > >
> > > Still no sound in the Pacemaker Demo.
> > >
> > 
> > It seems  there's a problem when microwire mixer is set.
> > 
> > Demo set mask to 0xc1ff and data to 0x8000, which should decode as 
> > command 10 000 000000 and set mixer=0.
> > 
> > But as it was tested lately on real STE (see 
> > http://www.atari-forum.com/viewtopic.php?f=3&t=26360&start=250#p252373
> > , mixer=0 doesn't give any sound. So, this was recently modified in Hatari.
> > 
> > But this demo use a non standard mask of 0xc1ff instead of 0x7ff, maybe 
> > in that case the microwire ignores the command and we should keep the 
> > value set by TOS, which is mixer=1.
> 
> I believe you are correct ( 0xc1ff erroneously contravenes specifications).
> 
> > 
> > I need to check that in the microwire doc.
> > 
> > Nicolas
> > 
> 
> I looked at the LMC1992 data sheet, here is what I surmise:
> 
> 1) The mask must be at least eleven consecutive bits long, or the
>    LMC1992 is left in an intermediate state, and restarts the sequence
>    when there is a break in the mask. Think of the Mask as an enable
>    signal.
>    (Six usable 11 bit Masks. eg. 0011111111111000, 0000011111111111)
>    (Five usable 12 bit Masks)
>    (Zero usable Masks less than 11 bits long)
> 
>    Note that it may be possible to send two (or more) 16 bit Masks that
>    act as a single 32 bit Mask.
>    ( 0000000000011111, 1111110000000000 )
> 
> 2) The first two Mask bits are a device address. The last nine bits
>    are register bits. Any bits between the first two and last nine are
>    lost when the Mask is longer than eleven bits.
> 
>