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

Gabriel Ambuehl gabriel_ambuehl at
Tue Dec 12 21:54:17 CET 2006

On Tuesday 12 December 2006 21:31, Robert Michel wrote:
> Replace "FPGA" with "CPLD" - CPLD keep it's configuration for > 20 years
> and allows 10 000 times of reprogramming.

I still imagine it needs more power and space than a ASIC wouldn't it?

> > 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?

Someone in the channel tossed a 3K USD figure around. But it is obviously a 
niche product, that might get cheaper quickly when ordered in volume...

> > 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.

Same for the FPGA. That one actually needs custom chip design even.

> 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.

Well that is obviously something else than running half the phone on the FPGA 
(which is what some seem to be aiming at).

> > 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.

I dont think you cound go round and stick a FPGA into Neo1973 at this point of 
time, either. 

> > 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.

Well that's why it should be a faster SoC in the heart. One that does USB2 
natively, for one. As for WiFi, well deactivating it would obviously help 
power ;)

> 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.

I'm not an EE either, but I imagine the closely cramped space inside a phone 
will make for all matters of interferences. Just think about your average on 
board soundcard. DJs wouldn't use that.

Now, as for using an external USB soundcard to do the actual DA conversion, 
that's feasible with USB1 even (if the Samsung chip can guarantee latency).

>olrunner_ii_cplds/advantages/low_power_consumption.htm 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?

It might. But it's not really an FPGA for use anymore if it fills a vital role 
in the system itself unless you chose one that is drastically overbuilt at 
which point the power consumption comes into play again.

> Even when you and Koen are disagree with my intention,
> even when my ideas are not soooo based on hardware skills,

Not an EE either.

> 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.

I agree. But I tend to view hardware as opaque stuff. Once it is made (and 
this point it better be "made" if it's going to be shipping in January), it's 
the way it is and the next generation should learn from it...

> And a potential that goes further than just a phone will
> open the Neo1973 to be used as
> smartphone = mobil PC + GSM/GPRS (+AGPS)

I agree. I just don't think the FPGA is really needed for that. More dedicated 
hardware and some more general purpose CPU power would help more (it surely 
would be useful if the SoC could actually do VGA @ 30FPS) in the next 

> But with a little bit smarter design OpenMoko could beat every
> PDA.

AFAIC, it will do that the day it gets WiFi ;)

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