The audio IC Wolfson WM8753 is cool :)))))

Robert Michel openmoko at
Tue Dec 12 21:31:45 CET 2006

Salve Gabriel!

Gabriel Ambuehl schrieb am Dienstag, den 12. Dezember 2006 um 20:20h:

> On Tuesday 12 December 2006 18:15, Richard Franks wrote:
> > > As can a GPIO. Stop with the fpga nonsense and get a devboard to play
> > > with
> >
> > That's a little bit harsh, dude. I agree that an FPGA is not a panacea,
> > but all we have is ideas just now, so there's no harm playing with them!
> Not meaning to offend, but it does seem a bit ill-conceived to stick a power 
> and room hungry FPGA (the whole point of those things is to be flexible, yes, 
> but that use comes at a cost) on a portable device that runs on battery and 
> then make everyone who wants the NeoXXXX foot the bill. 

Replace "FPGA" with "CPLD" - CPLD keep it's configuration for > 20 years and
allows 10 000 times of reprogramming.

> I'd much rather have you guys convince FIC to add some sort of real expansion 
> slot (something along the line of mini PCI or PC 104 or heck make it CF1 and 
> stick into it). 
hmmm nice - anybody a clue about the price?
> A stub 
> connector on the back side would be enough (and would not considerably 
> increase the size of the device when not in use)so you can stick big modules 
> on the back of YOUR devices (see those iPaq addons of years gone by).

This would be a new interface, new hardware componets.

I'm focusing on the idea how make as much of the given hardware power of the SoC 
and the audio IC usable as possible.

> For 99% of the intended audience (which is already somewhat geekier than your 
> average cell phone owner at least for starters) a faster CPU (Freescale 
> 31 anyone ;) 
The CPU decision is made - not the time to change this.
> and some more hardware on board (USB2 and WiFi out of the box) 
Will be also consume power and the need to deactivate this ICs to
reduce the power consumption when this is not used.

> will be orders of magnitude more useful than a FPGA (a concept that is 
> unknown to most anyhow). For those who really want to hack the hardware, they 
> can still get their own FPGA.

When there is a solderpoint for SPI it will be possible to solder an
FPGA. It will also possible with some effort to solder the FPGA
inbetween the mini-USB and the audio jack. But *NO* chance to access
wasted power of the Wolfson WM8753 - e.g. solution like to have 
2 high quality audio output and
1 low quality mono audio output for DJs.

> It just doesn't make economic sense to put a FPGA in a phone that's supposedly 
> for the mass market. Not in my book anyway.

I have a different point of view - look what power the SoC and the Wolfson
WM8753 has - why not use a CPLD as multiplexer to use the full power of
the already choosen hardware?

Consider, one stereo audio jack 2,5mm could switched to be SPI or I2C
- a big playfield for hackers, hams, sensors but also for some
  comercial accessories - or use the Neo1973 as interface for service
  tasks (remote service for professional TV cameras, photo copier,

So what about a CPLD like this
Beside multiplexing IOs (and also the memory SD-card slot and SIM
card)... Does such a component not have the potential in a ciruit to 
save more power with the posibility to swich of (with 100%) the power 
supply for other components, than it needs itself?

Even when you and Koen are disagree with my intention,
even when my ideas are not soooo based on hardware skills,
I think our dispute is fruitfull because we all love to 
be able to use as much as possible of the hardware hardware 
potential on the used components.
And a potential that goes further than just a phone will 
open the Neo1973 to be used as 

smartphone = mobil PC + GSM/GPRS (+AGPS)

and this kind of openess that we like will let OpenMoko/Neo1973
stand out from the crowd of unsmartphones.
(of course I do not forget the core function for what users
will use their phone ;)
But with a little bit smarter design OpenMoko could beat every


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