GPIO link Re: The audio IC Wolfson WM8753 is cool :)))))

Robert Michel openmoko at
Wed Dec 13 00:12:55 CET 2006


Robert Michel schrieb am Dienstag, den 12. Dezember 2006 um 18:51h:

> Salve Koen!
> On Tue, 12 Dec 2006, Koen Kooi wrote:
> > > PS: Again, it seems that an FPGA between the I/O connectors
> > >     and the other chips would encrease the power of the Neo1973,
> > >     e.g. the FPGA could switch the second audio jack to mono output.
> > 
> > As can a GPIO. Stop with the fpga nonsense and get a devboard to play with

> Just conventional design of a smartphone would wast much of the I/O
> power of the SoC (eg. SPI) of the audio ic and of the I/O connector
> of the device.
> The WM8753 has 2 ADC and 2 DAC +1VoiceDAC  and the possiblity to switch
> 2 line in and 2 mic in, and has multiple out but no chance to route an
> DAC to an ADC line.
> And the SoC has several interesting I/Os, but the Neo1973 will have
> only a mini-USB and one stereo 2,5mm audio jack (or I hope a second
> 2,5mm audio jack).
> With out ground line makes this 3+2(+2) = 5 (7) lines
> with gound connector 4+3(+3) = 7 (10) I/O contacts.
> Will a GPIO help to totaly free to switch SPI USB audio in/out to
> any to this lines? Could you give me a link for GPIO knowledge?

The WM8753 hasen't GPIO support, but the WM9714 would
But I don't see how GPIO could switch an audio-in jack to
be a second audio-out jack (third audio-out channel) so that
the Neo1973 would have 1 stereo line out and one mono headphone out.

I thing it is cool that the WM8753 has 3 channel DAC audio out and it
would worth it to make all 3 usable simultanious ;)

> So could you stay constructive and explain how "GPIO" coudl help to use 
> the full power given with the WM8753 and S3C2410 and the external
> connectors of the Neo1973?

GPIO would not help to make SPI usable externaly, right?


PS: Wolfson DAC are used for the ipod:

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