
A BeagleBone on a Chip - unwind
http://hackaday.com/2016/05/10/new-part-day-a-beaglebone-on-a-chip/
======
2bluesc
I don't understand the real value in this. They take a bunch of BGA parts +
passives and put the dies in a bigger BGA that approaches the same PCB area?

If someone has the manufacturing capability to put down one integrated BGA
part, then they have the capability of putting down the DRAM and processors
just the same as well as the 0201s or whatever passives to support it.

Only thing it seems to do is enable quicker prototyping by avoiding having to
get things like the DDR memory traces correct. And a shorter BOM.

On the flip side, single source supplier, fewer memory options, fewer chip
configuration options, etc. Places with the manufacturing capability of BGAs
and 0201 probably aren't distracted much by 50(guess?) additional BOM line
items and the reels of parts to realize that.

Also, how many hackers are actually putting down BGAs like this when you can
buy a properly routed, tested and assembled BeagleBone for so cheap? I know a
few are, but they are the 0.1% perhaps? All the makers are rocking Arduinos
and Raspberry Pis and can't even spell B-G-A.

I was initially intrigued thinking it was considerably smaller, but it doesn't
appear so. [0][1]

Anyone have a different take on this?

[0]
[http://www.digikey.com/Web%20Export/techzone/microcontroller...](http://www.digikey.com/Web%20Export/techzone/microcontroller/article-2013june-
life-after-pi-fig2.jpg) [1]
[http://i0.wp.com/octavosystems.com/octavosystems.com/wp-
cont...](http://i0.wp.com/octavosystems.com/octavosystems.com/wp-
content/uploads/2016/05/OSD3358-SBC-Front.jpg)

~~~
tomstokes
> I don't understand the real value in this. They take a bunch of BGA parts +
> passives and put the dies in a bigger BGA that approaches the same PCB area?

It's like DRY (don't repeat yourself) for embedded systems. This package wraps
the common layout tasks of an embedded systems design in to an easy, pre-
packaged module. The PCB designer no longer has to do the layout work of all
of the DRAM and power-supply traces, which can consume a lot of time and
effort when you're just trying to do a basic design.

> If someone has the manufacturing capability to put down one integrated BGA
> part, then they have the capability of putting down the DRAM and processors
> just the same as well as the 0201s or whatever passives to support it.

That's the other great thing about this package: The BGA pitch (distance
between BGA balls) is a relatively large 1.27mm. This allows for the use of
much cheaper PCB processes because the designer doesn't have to use very fine
vias and traces to route in between the balls. For reference, many BGA
packages these days have 0.8mm, 0.5mm, or even 0.4mm pitches and require more
expensive PCB processes for the entire board just to place that one chip.

> Also, how many hackers are actually putting down BGAs like this when you can
> buy a properly routed, tested and assembled BeagleBone for so cheap? I know
> a few are, but they are the 0.1% perhaps? All the makers are rocking
> Arduinos and Raspberry Pis and can't even spell B-G-A.

Placing BGAs is quite easy for the hobbyist these days, especially now that
hot-air stations can be had cheaply. You're right though, in that this product
isn't targeted at the weekend DIYer. It's for people building boards who want
a CPU but don't want to mess with tight PCB tolerances and all of the high-
speed routing required. It also represents a very easy path toward
manufacturing for those DIYers who do start with a BBB-based design and want
to move to something they can mass produce and sell.

With this, they could drop a single, easy BGA package on their PCB and skip
straight to doing design and layout only for the parts of their design that
differ from every other embedded systems design (e.g. not the DRAM <-> CPU
interface, not the power supply layout, and so on).

------
bsder
Shrug. It's okay, but there's still a lot of passives floating around on that
reference design.

By contrast, some of the Freescale Cortex parts don't even need crystals to
run USB (they use the USB signalling to tighten up the on-chip PLL/VCO). And
they don't need capacitors on the crystal pins. So, you can use one of those
Cortex parts with basically a USB connector, a switching power supply chip,
some bypass caps _AND THAT 'S IT_.

I also really don't understand why nobody integrates the ethernet PHY at this
point. It would change from 20 pins to something like 5 pins.

Microchip has had a PIC18F97J60 for years. Why is nobody else doing this in
the more advanced SoC's?

~~~
sdk77
Allwinner (A10, etc) SoCs have it. You still need the connector with
integrated magnetics though.

------
jschwartzi
This fills a market that is currently only served with low-cost SOMs. The
company I work for could directly replace the AM3354-based SOM that I write
software for with this chip, especially if it brings out the GPMC, MMC, and a
couple UARTs.

Does anyone know how the pinmux works on this part?

~~~
_pmf_
Phytec?

~~~
jschwartzi
No, it's made by a different company.

------
smoyer
"have hundreds of passive components sprinkled around the board"

Resistors, inductors and capacitors are used to match the characteristic
interface impedance (RLC) for many types of interfaces - there's often a
integrated matching component near your Ethernet port. Capacitors are also
used to "quiet" the power supply lines as they enter the integrated circuits.

These passive components are rarely used when interconnecting the different
"chips" in a system as you design your system to use compatible parts. And
with additional integration in the SoC, I'm guessing you'll need additional
capacitors around the chip.

In short (too late?), I'm skeptical as to whether it will reduce the number of
passive components at all. It will definitely make laying out a circuit board
easier (except with BGA, you'll need multi-layer anyway).

~~~
ausjke
Layout with a SOM might be much easier than with this BGA enclosure.

~~~
joezydeco
SOMs need large connectors and, as I've found out recently, the DIMM
connectors radiate a ton of EMI at LCD pixel clock speeds. Getting a proper
heat sink is mechanically challenging too.

At this point I'd rather have the BGA that I can place on a low-speed PCB.

------
revelation
There are bazillions of these "system modules" available for any kind of CPU,
here is one for the AM335x:

[http://www.myirtech.com/list.asp?id=467](http://www.myirtech.com/list.asp?id=467)

[http://phytec.com/products/system-on-
modules/phycore/am335x/...](http://phytec.com/products/system-on-
modules/phycore/am335x/#som)

You can buy these with any level of high-density connector you desire, if you
need all those pins. No need for a big messy BGA device.

------
shortsightedsid
As of today, there isn't much of an advantage of doing a SiP for a chip like
the AM335x other than the high speed design. Most of market is still with PCB
SoMs for larger cortex-A chips.

The real advantage of SiP is with BLE or similar. That's because not only do
they take away the complexity of RF design, and regulatory certification i.e
FCC, IC, CE etc.. The market for BLE SiP modules that integrate the crystal,
Balun, Antenna and are are certified is exploding.

Just a year ago, the cost difference between a BLE module and BLE chip was
large enough to justify doing a custom design for anything more than 5K
Units/Year. However, the Math is slowing moving towards higher and higher
volumes. Already anything that ships less than 20K-30K per year doesn't
justify the cost of doing a custom RF design.

Maybe in a couple of years, there will be a mass market for Beaglebone SiPs.
Just not yet.

------
ae_keji
The real exciting part about this (to me) is the potential for a full fledged
linux altoids tin computer. Suddenly the something like the Pyra/Open Pandora
is a lot more realistic. Or even a (usable) hobbyist diy phone.

