One pin, one component oscillator with GA144

Chuck Moore has published the code to run an oscillator on one
processor of a GA114 chip. It uses a single 10 Mhz resonator and no
other components hanging off one pin. This works in principle also
with a crystal (which led to some controversy here), but it is harder
to get started because of the enormous q-factor of a crystal.

This hinges on submicrosecond switching between input and
output on the same pin, and the ability to wait for a zero
and the ability to wait for a one on that same pin.

http://www.colorforth.com/b942.htm
(6 lines of code and two lines starting the oscillation.)

To understand the code you may need a visit to
http://www.colorforth.com/etherCode.htm
http://www.greenarraychips.com/index.html

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

On Jun 28, 11:38=A0am, Albert van der Horst <alb...@spenarnc.xs4all.nl>
wrote:
> Chuck Moore has published the code to run an oscillator on one
> processor of a GA114 chip. It uses a single 10 Mhz resonator and no
> other components hanging off one pin. This works in principle also
> with a crystal (which led to some controversy here), but it is harder
> to get started because of the enormous q-factor of a crystal.
>
> This hinges on submicrosecond switching between input and
> output on the same pin, and the ability to wait for a zero
> and the ability to wait for a one on that same pin.
>
> http://www.colorforth.com/b942.htm
> (6 lines of code and two lines starting the oscillation.)
>
> To understand the code you may need a visit tohttp://www.colorforth.com/e=
therCode.htmhttp://www.greenarraychips.com/index.html
>
> Groetjes Albert

Yes, the controversy is because this has limited utility.  He states,
"A resonator has a lower Q than a crystal and is much easier to start
oscillating." which says to me that using a crystal doesn't work.  He
also gives no performance specs on the resulting circuit or even info
on how this was tested.  So even with a resonator I can't verify that
this is a "working" circuit in a practical sense.  Does it drift with
temperature, does it start at temperature extremes?  Does it work
reliably when you build 100's or even 1000's of them?  Another quote
from the page, "The number of unexts in a us may need to be adjusted
for different chips or temperatures."  I think that says it all!

For now I am still planning to use an oscillator.

Rick

In article <ff4bf720-6ce9-49c0-9464-c5de3b0fe690@j10g2000yqd.googlegroups.com>,
rickman  <gnuarm@gmail.com> wrote:
>On Jun 28, 11:38=A0am, Albert van der Horst <alb...@spenarnc.xs4all.nl>
>wrote:
>> Chuck Moore has published the code to run an oscillator on one
>> processor of a GA114 chip. It uses a single 10 Mhz resonator and no
>> other components hanging off one pin. This works in principle also
>> with a crystal (which led to some controversy here), but it is harder
>> to get started because of the enormous q-factor of a crystal.
>>
>> This hinges on submicrosecond switching between input and
>> output on the same pin, and the ability to wait for a zero
>> and the ability to wait for a one on that same pin.
>>
>> http://www.colorforth.com/b942.htm
>> (6 lines of code and two lines starting the oscillation.)
>>
>> To understand the code you may need a visit tohttp://www.colorforth.com/e=
>therCode.htmhttp://www.greenarraychips.com/index.html
>>
>> Groetjes Albert
>
>Yes, the controversy is because this has limited utility.  He states,
>"A resonator has a lower Q than a crystal and is much easier to start
>oscillating." which says to me that using a crystal doesn't work.  He

Why so negative? Why not admit that this chip is an interesting
and curious experiment?

>also gives no performance specs on the resulting circuit or even info
>on how this was tested.  So even with a resonator I can't verify that
>this is a "working" circuit in a practical sense.  Does it drift with
>temperature, does it start at temperature extremes?  Does it work
>reliably when you build 100's or even 1000's of them?  Another quote
>from the page, "The number of unexts in a us may need to be adjusted
>for different chips or temperatures."  I think that says it all!

This is plain dishonest. Let me site another line:
"
  Neither us or ms is used here. I leave the code in clock as a
  reference copy that I may be able to find.
"
So he jotted down a delay routine, so what?

>
>For now I am still planning to use an oscillator.

Of course! It will take forever before we see application notes
from GreenArrays.  Maybe you'll see those from us (Dutch Forth
users) first.

>
>Rick

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

On Thu, 28 Jun 2012 19:44:40 +0000, Albert van der Horst wrote:

> In article
> <ff4bf720-6ce9-49c0-9464-c5de3b0fe690@j10g2000yqd.googlegroups.com>,
> rickman  <gnuarm@gmail.com> wrote:
>>On Jun 28, 11:38=A0am, Albert van der Horst <alb...@spenarnc.xs4all.nl>
>>wrote:
>>> Chuck Moore has published the code to run an oscillator on one
>>> processor of a GA114 chip. It uses a single 10 Mhz resonator and no
>>> other components hanging off one pin. This works in principle also
>>> with a crystal (which led to some controversy here), but it is harder
>>> to get started because of the enormous q-factor of a crystal.
>>>
>>> This hinges on submicrosecond switching between input and output on
>>> the same pin, and the ability to wait for a zero and the ability to
>>> wait for a one on that same pin.
>>>
>>> http://www.colorforth.com/b942.htm (6 lines of code and two lines
>>> starting the oscillation.)
>>>
>>> To understand the code you may need a visit
>>> tohttp://www.colorforth.com/e=
>>therCode.htmhttp://www.greenarraychips.com/index.html
>>>
>>> Groetjes Albert
>>
>>Yes, the controversy is because this has limited utility.  He states, "A
>>resonator has a lower Q than a crystal and is much easier to start
>>oscillating." which says to me that using a crystal doesn't work.  He
> 
> Why so negative? Why not admit that this chip is an interesting and
> curious experiment?
> 
>>also gives no performance specs on the resulting circuit or even info on
>>how this was tested.  So even with a resonator I can't verify that this
>>is a "working" circuit in a practical sense.  Does it drift with
>>temperature, does it start at temperature extremes?  Does it work
>>reliably when you build 100's or even 1000's of them?  Another quote
>>from the page, "The number of unexts in a us may need to be adjusted for
>>different chips or temperatures."  I think that says it all!
> 
> This is plain dishonest. Let me site another line:
> "
>   Neither us or ms is used here. I leave the code in clock as a
>   reference copy that I may be able to find.
> "
> So he jotted down a delay routine, so what?

Saying the comment is dishonest is way too strong.  Had I read the 
website before I saw your comment, I would paired "oscillator" with "way 
huge variance in constants for timing" and come up with "crappy" myself.

And, if the oscillator isn't crappy for needing such adjustments, the 
code sure is for being misleading.

>>For now I am still planning to use an oscillator.
> 
> Of course! It will take forever before we see application notes from
> GreenArrays.  Maybe you'll see those from us (Dutch Forth users) first.




-- 
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

On Jun 28, 3:44=A0pm, Albert van der Horst <alb...@spenarnc.xs4all.nl>
wrote:
> In article <ff4bf720-6ce9-49c0-9464-c5de3b0fe...@j10g2000yqd.googlegroups=
.com>,
>
> rickman =A0<gnu...@gmail.com> wrote:
> >On Jun 28, 11:38=3DA0am, Albert van der Horst <alb...@spenarnc.xs4all.nl=
>
> >wrote:
> >> Chuck Moore has published the code to run an oscillator on one
> >> processor of a GA114 chip. It uses a single 10 Mhz resonator and no
> >> other components hanging off one pin. This works in principle also
> >> with a crystal (which led to some controversy here), but it is harder
> >> to get started because of the enormous q-factor of a crystal.
>
> >> This hinges on submicrosecond switching between input and
> >> output on the same pin, and the ability to wait for a zero
> >> and the ability to wait for a one on that same pin.
>
> >>http://www.colorforth.com/b942.htm
> >> (6 lines of code and two lines starting the oscillation.)
>
> >> To understand the code you may need a visit tohttp://www.colorforth.co=
m/e=3D
> >therCode.htmhttp://www.greenarraychips.com/index.html
>
> >> Groetjes Albert
>
> >Yes, the controversy is because this has limited utility. =A0He states,
> >"A resonator has a lower Q than a crystal and is much easier to start
> >oscillating." which says to me that using a crystal doesn't work. =A0He
>
> Why so negative? Why not admit that this chip is an interesting
> and curious experiment?

I am expressing a negative opinion of the "one pin oscillator" because
I find it has little or no use in most designs.  Yes, I agree that it
is an interesting experiment, but this feature has no value in a
commercial product, which is how GA is currently promoting the
GA144.


> >also gives no performance specs on the resulting circuit or even info
> >on how this was tested. =A0So even with a resonator I can't verify that
> >this is a "working" circuit in a practical sense. =A0Does it drift with
> >temperature, does it start at temperature extremes? =A0Does it work
> >reliably when you build 100's or even 1000's of them? =A0Another quote
> >from the page, "The number of unexts in a us may need to be adjusted
> >for different chips or temperatures." =A0I think that says it all!
>
> This is plain dishonest. Let me site another line:
> "
> =A0 Neither us or ms is used here. I leave the code in clock as a
> =A0 reference copy that I may be able to find.
> "
> So he jotted down a delay routine, so what?

The resonator has to be started with timed kicks.  He backed off from
using a crystal because he couldn't get that to work over Process,
Voltage and Temperature (PVT, but not the Boyle's Law PVT).  There
isn't enough timing resolution using a 1.5 ns instruction cycle to
reliably and consistently start a crystal.  I don't know that even a
resonator will start reliably.  Currently Chuck is "experimenting",
not designing or writing app notes for a commercial product.


> >For now I am still planning to use an oscillator.
>
> Of course! It will take forever before we see application notes
> from GreenArrays. =A0Maybe you'll see those from us (Dutch Forth
> users) first.

Actually, I'm glad you posted your comment here.  It gave me a chance
to take a  fresh look at what Chuck is doing.  I have been looking for
a product to sell and have been short on ideas for some time now.  A
couple of weeks ago it occurred to me that the GA144 might be the
basis of a low end, very low cost oscilloscope.  I'm having a little
trouble figuring out how to design around the memory size and speed
limitations of the device as well as the clocking problems.  At some
point I started to think about adding a dedicated display possibly
through a VGA port and realized that might be pretty easy for moderate
resolutions.  I did some timing analysis and found it should work at
up to 1024x768 resolution with the overall pixel, line and frame
clocks being easy to generate.  But then it started to fall apart.
For a full graphic application, the memory access rate was higher than
what the memory used on eval board is capable of much less the 5x
slower implementation the GA design uses.  I quickly realized that I
would only be able to support a text display which has a much lower
memory access speed.

Your post lead me back to Chuck's pages which I think I read some
months ago and mostly forgot.  I found the part where he discusses his
video design and realized that he is truly experimenting to see what
he can do with "real time" video processing.  He is not trying to
design a practical video display.  He has generated the timing strobes
and put up a blue background and has yet to begin confronting the real
limitations of this device in producing a video display.

I haven't given up on using the device as the core of a very low cost
oscilloscope, but it will clearly need supporting devices.  Most
notably a high speed USB interface which may be hard to interface to
the GA144 chip since it has no high speed interfaces for non-GA144
devices.  That was part of the motivation for using the GA144 for a
video display, give up on a high speed USB.  Even using two GA144s may
not do the job (one of oscope front end and one for video display)
since the video is not suited for graphics that I can tell.  I'm going
to look at the now obsolete video DRAMs.  They could stream an entire
page of memory with one setup delay.  Or maybe DDR.  This thing has to
have faster memory.

Rick

In article <8fdc084b-6b6f-41e4-ab4c-17053fd134e6@d24g2000yqh.googlegroups.com>,
rickman  <gnuarm@gmail.com> wrote:
<SNIP>
>
>I haven't given up on using the device as the core of a very low cost
>oscilloscope, but it will clearly need supporting devices.  Most
>notably a high speed USB interface which may be hard to interface to
>the GA144 chip since it has no high speed interfaces for non-GA144
>devices.  That was part of the motivation for using the GA144 for a
>video display, give up on a high speed USB.  Even using two GA144s may
>not do the job (one of oscope front end and one for video display)
>since the video is not suited for graphics that I can tell.  I'm going
>to look at the now obsolete video DRAMs.  They could stream an entire
>page of memory with one setup delay.  Or maybe DDR.  This thing has to
>have faster memory.

USB... I was distressed at seeing dedicated USB chips on the
development board. The GA144 should be able to do its own
USB, or all the hype is, well, just hype. If I where at Green Arrays
the GA144 would already have been registered as a USB device, awaiting
the software. (the slowest should be doable, heck the Arduino
is doing bit banged  USB of sorts.)

Lately I was thinking of a typically Dutch application:
a fiets (bike) computer on solar. There is a market
for a bike computer without batteries, because
it could be hermetically sealed and very sturdy and sport a
deft prevention device. Once you're established in the
high end of this market, you may become even profitable!
People are sinking money into their hobby and the
properties of the device may be hard to replicate.
(Most competition would face memory loss.)

I have looked into vintage DDR ram for laptops. I got those
for cents/Mbyte. This is available in plenty and the
CAS/RAS interfacing could be left to the chip doubling
the address lines as it where. Experimenting costs time, not
money.

>
>Rick

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

On Jul 1, 8:40=A0am, Albert van der Horst <alb...@spenarnc.xs4all.nl>
wrote:
> In article <8fdc084b-6b6f-41e4-ab4c-17053fd13...@d24g2000yqh.googlegroups=
.com>,rickman =A0<gnu...@gmail.com> wrote:
>
> <SNIP>
>
> >I haven't given up on using the device as the core of a very low cost
> >oscilloscope, but it will clearly need supporting devices. =A0Most
> >notably a high speed USB interface which may be hard to interface to
> >the GA144 chip since it has no high speed interfaces for non-GA144
> >devices. =A0That was part of the motivation for using the GA144 for a
> >video display, give up on a high speed USB. =A0Even using two GA144s may
> >not do the job (one of oscope front end and one for video display)
> >since the video is not suited for graphics that I can tell. =A0I'm going
> >to look at the now obsolete video DRAMs. =A0They could stream an entire
> >page of memory with one setup delay. =A0Or maybe DDR. =A0This thing has =
to
> >have faster memory.
>
> USB... I was distressed at seeing dedicated USB chips on the
> development board. The GA144 should be able to do its own
> USB, or all the hype is, well, just hype. If I where at Green Arrays
> the GA144 would already have been registered as a USB device, awaiting
> the software. (the slowest should be doable, heck the Arduino
> is doing bit banged =A0USB of sorts.)

There are two reasons why USB will not be native in the GA144 any time
soon.  One is that to be really useful it needs to be High Speed at
480 Mbps and that ain't happenin' in software.  I thought they might
find a way to use the SERDES, but I think that is a VERY remote chance
since it seems to be timed by the chip and not a clock.  The other and
truly limiting feature is the software.  I can't imagine partitioning
a USB stack into the tiny pieces that can be implemented on the
GA144.

Am I wrong about either of these?

They may someday implement a very limited Full Speed USB slave, but I
doubt you will ever see a master implementation without support
chips.


> Lately I was thinking of a typically Dutch application:
> a fiets (bike) computer on solar. There is a market
> for a bike computer without batteries, because
> it could be hermetically sealed and very sturdy and sport a
> deft prevention device. Once you're established in the
> high end of this market, you may become even profitable!
> People are sinking money into their hobby and the
> properties of the device may be hard to replicate.
> (Most competition would face memory loss.)

Yes, that could be a useful product, but why would it need a GA144 at
$12 each?  There are lots of good MCU devices with very low power
features that should be able to easily implement such a device.
Energy Micro has a very low power ARM and I often hear about how low
power an MSP430 can be.  They are currently much lower power than the
one GA used in their energy comparison that is now two years old.

BTW, check out the thread here on "Open source writswatch ?".  That
device with very few mods (like a lower power focus) could be device
you are describing.


> I have looked into vintage DDR ram for laptops. I got those
> for cents/Mbyte. This is available in plenty and the
> CAS/RAS interfacing could be left to the chip doubling
> the address lines as it where. Experimenting costs time, not
> money.

Time IS money!!!

I don't know if DDR is needed, I did a survey and tossed the DDR chips
I found, possibly because of the dual phase clock required.  But SDRAM
should be easy to interface to the GA144, but to what end?  It is
still slow for single accesses (~70 ns with 100 MHz clock which may
not be realistic).

I was just researching using SDRAM and I found references in the
documents saying the ROM for nodes 007, 008 and 009 supports SDRAM!
So why do they use async ram on the eval board?  WTF?

I'm actually very frustrated trying to learn the tools and device.  A
lot of the documentation includes features that aren't implemented or
don't work and much of it assumes you have mastered other stuff
first.  The order of precedence is not at all clear to me and I am
having a hard time getting to the point where I know enough to
determine if the SDRAM interface is practical at 100 MHz.  If you have
to slow down the interface much the cycle time gets too slow to be
worth doing.

If I can rant a little more, reading Chuck's pages doesn't help much.
His approach is so far from mainstream that I don't get much
"education" from it.  For example he is trying to implement a video
interface that doesn't use a pixel clock and has no video memory!  So
far he has generated the sync pulses and put up a solid blue screen.
Yep, that's the sum total of some six months or more of work.  At
least that is all he has documented.

The GA page is not much better.  I looked at the arrayForth Institute
page and signed up for PROG100.  It has two parts, one is available
and the other will not be ready until later in March 2012.  I think
that says it all.  Also, I can't seem to get the first lesson to
work.  Oh well...

Rick