[Arm-netbook] AMD APU's in EOMA and ARM SOC's with PCIe

[lkcl luke]

2012/1/22 Henrik Nordström <henrik at henriknordstrom.net>:
> sön 2012-01-22 klockan 18:53 +0000 skrev lkcl luke:
>> want to put it on the connector because a simple USB audio driver IC
>> or even an STM32F with a Class D (PWM) amplifier on the back would do
>> the same job.
>
> I was just about to say the same.
>
> High def audio in EOMA connector do not make much sense. USB is quite
> sufficient for high def audio, and wonderfully
> cross-platform/cpu/chipset/whaterver compatible, so lets not waste
> energy on agreeing on what kind of advanved audio interface to use in
> the EOMA interface standard. If anything then simple analog stereo audio
> for driving internal speakers in tablet/notebook, but serisouly the cost
> of a stereo USB chip is pretty marginal I think?

 they're the sort of thing that goes into those MP3 players,
typically, and as such are something like $1 to $1.50.

> For this form factor to work for tablets/notebooks use case there MUST
> be some display connection however. And probably something for
> touchscreen unless USB is used for that.
>
> The only I worry that USB for both audio and touchscreen may add a bit
> too much on the base unit BOM (audio controller, touch controller, hub)

 that's why, again, i figured on doing all of those in software, using
an STM32F.  bit-banging on a capacitive touchpanel controller if
absolutely necessary: it's not like a 72mhz Cortex M3 has anything
else to do.

 you can see from this page http://olimex.com/dev/stm32-h103.html that
someone has already written a mouse driver - in software.

 so instead of $1.50 for an audio IC, $1.50 for a touchscreen
controller, $2.50 for a battery charger IC, $1.50 for a PWM LCD
backlight controller, you have.... $1.50 for an STM32F and that's it.


> I am not sure at all on LAN. My gut feeling is that LAN is better suited
> as an external edge connector.

 yehh except it doesn't quite fit onto a PCMCIA (6mm) card, there's
not enough room for any other connectors, and you know what happens to
"dongles" - they break, or are lost.

> I mean LAN always goes to the CPU only,
> and we need the PHY on board anyway or it will be a mess. Routing
> gigabit ethernet via the EOMA connector and some base board do not
> exactly smell any good at all to me and is likely to mess up and crash
> with FCC signal emission regulations etc. Don't go there.

 well... gigabit ethernet i read somewhere is 5 sets of
spread-spectrum frequencies over each of the 4 balanced-line pairs
(!).  in other words it's *not* 1ghz frequency, nor even 500mhz.

 even if it was 500mhz, that's still a lot less than SATA-II which is
3gb/sec LVDS, and we're considering putting that on.


> So for the EOMA connector I end up with
>
> - SATA (high perf storage in base unit)
> - Some suitable display interface for connecting an internal panel
> (laptop & tablet usage). I.e. LVDS or MIPI DSI.
> - i2c
> - USB (Keyboard, mouse, audio, basic storage)
> - Power
> - Optionally analog stereo audio, but may be routed over USB

 yeah i keep coming back to this (analog stereo audio) but then i
think "argh that means it has to be part of the standard".

 i was thinking of sneaking it in (breaking the standard, overriding 2
of the GPIO pins) for some projects, but even there i still go "argh"
:)

> - Maybe something for touch screen interface. But USB is an option there
> as well.

 yes.  again, see above: resistive touch can be done using ADCs on an STM32F.

> Probably
>
> - HDMI, for smart-TV controller usage. But maybe not suitable as display
> interface dor laptop/tablet case above. Or is it? Interface needs to
> support HDCP.

 you can put that on the external user-facing end, as a standard HDMI
connector.  then you don't have to get concerned about HDCP, it just
goes out as normal (as you would a standard motherboard design)

> - If something else than HDMI is used then SPDIF audio.
>
> And NOT
>
> - High def audio (USB & HDMI both serves that purpose nicely)
> - LAN
>
>
>
> External edge connectors:
>
> - HDMI
> - Micro-USB AB
> - Headphones
> - LAN, special cable, or double size PCMCIA, or extending externally.
> Would recommend extending externally.
> - Antenna for wifi/bt on cards having such functionality built in.
> Antenna can also be builtin by extending the card a bit externally.

 yes i thought about that, too - but not for the first version(s):
there's enough to be going on with, without worrying about R.F. as
well.
>
> Internal Edge:
>
> - MicroSD storage for increased persistent storage. Could even be the
> sole storage (no NAND required).

 yep.

> - Recovery switch.

 ah forgot about this one.

> Both behind a small sealed door to keep edge clean in normal usage and
> avoid accidental loss of SD card in transport. See Trimslice design if
> you wonder what I mean.

 yep.

 ah wait - that means you have to have a redesigned case-work.  unless
you embed it into the plastic.

> Internal:
>
> - Extension connector. Accessible when without cover, or by having a
> flip cover opening which can be opened if needed (held in place by screw
> or metal spring effect).

 ah that again means casework redesign.

 l.