> rickman wrote:
>> The async processor goes to sleep until an input triggers it. So why
>> not use a clock for that input? Then the GA144 core could utilize
>> very little power just waiting.
> You wrote it above: Chuck stops the clock, there is no clock to be used
> during sleeping time.
> You can stop your clock in a serial interface after the stop bit,
> waiting for the next start bit (that's the purpose of the start bit, to
> provide a transition). You have to keep it running until the stop bit
> arrives.
I'm not sure what clock you are talking about. I'm talking about a clock that is used to measure the period of the async bits, a requirement in an async protocol.
The UART node can be stopped waiting for a transition on the input. When the start bit transition happens on the async input the UART node sends a message to the timer node which counts external timing clock edges to measure time. Meanwhile both nodes stop. The timer node waits for clock edges and the UART node waits for a message from the timer node as well as further edges from the async input. If the async input transitions first the bit is considered noise and the UART node starts over. If the timer message arrives first this marks the middle of the start bit. On subsequent timer messages the UART node reads the async input to get data and overhead bits.
I believe Chuck does not like to use an external clock because it is "extra" hardware and dissipates power. But a 5 mW node is not exactly a "light" footprint to do nothing other than mark time. I prefer the external clock.
> On Monday, October 8, 2012 1:31:55 AM UTC+2, rickman wrote:
>> what do you think you could use this device for
>> that would be a better implementation than other devices?
> I intend to use the GA144 to interface to one or more antennas. I have a"gut feeeling"
that if you remove all of the simplifying assumptions between electromagnetic radiation
and software you might be able to find some new properties of both.
> I am particularly interested in the orbital angular momentum ( OAM ) property of
electromagnetic radiation - I want to go back to basics and see whether this can be
measured easily with a GA144. I think the 6 GHz counter and VCO might be able to resolve
OAM effects. We shall see...
> Best regards,
> Howerd
OAM eh? What aspects of the GA144 will enable this to be measured better than other methods? The 5.6 GHz counter is just an ADC with a variable resolution vs. sample rate. There are lots of ADC available with very high sample rates and much better resolution.
On Tuesday, October 9, 2012 7:48:14 PM UTC+2, rickman wrote:
> On 10/8/2012 4:31 PM, Howerd wrote:
> > On Monday, October 8, 2012 1:31:55 AM UTC+2, rickman wrote:
> >> what do you think you could use this device for
> >> that would be a better implementation than other devices?
> > I intend to use the GA144 to interface to one or more antennas. I have a"gut feeeling"
> that if you remove all of the simplifying assumptions between
> electromagnetic radiation
> and software you might be able to find some new properties of both.
> > I am particularly interested in the orbital angular momentum ( OAM ) property of
> electromagnetic radiation - I want to go back to basics and see whether
> this can be
> measured easily with a GA144. I think the 6 GHz counter and VCO might be
> able to resolve
> OAM effects. We shall see...
> > Best regards,
> > Howerd
> OAM eh? What aspects of the GA144 will enable this to be measured
> better than other methods? The 5.6 GHz counter is just an ADC with a
> variable resolution vs. sample rate. There are lots of ADC available
> with very high sample rates and much better resolution.
> Rick
Hi Rick,
> OAM eh? What aspects of the GA144 will enable this to be measured > better than other methods?
The fact that there is minimum hardware between the antenna and the transistors that measure voltage - I am also looking for macroscopic quantum effects. If you read voltage using an ADC with amplifiers, filtering, anti-aliassing etc you are bound to observe what the theory says is there, because that theory was used to design the system. I want to get closer to the hardware.
> On Tuesday, October 9, 2012 7:48:14 PM UTC+2, rickman wrote:
>> On 10/8/2012 4:31 PM, Howerd wrote:
>>> On Monday, October 8, 2012 1:31:55 AM UTC+2, rickman wrote:
>>>> what do you think you could use this device for
>>>> that would be a better implementation than other devices?
>>> I intend to use the GA144 to interface to one or more antennas. I have a"gut feeeling"
>> that if you remove all of the simplifying assumptions between
>> electromagnetic radiation
>> and software you might be able to find some new properties of both.
>>> I am particularly interested in the orbital angular momentum ( OAM ) property of
>> electromagnetic radiation - I want to go back to basics and see whether
>> this can be
>> measured easily with a GA144. I think the 6 GHz counter and VCO might be
>> able to resolve
>> OAM effects. We shall see...
>>> Best regards,
>>> Howerd
>> OAM eh? What aspects of the GA144 will enable this to be measured
>> better than other methods? The 5.6 GHz counter is just an ADC with a
>> variable resolution vs. sample rate. There are lots of ADC available
>> with very high sample rates and much better resolution.
>> Rick
> Hi Rick,
>> OAM eh? What aspects of the GA144 will enable this to be measured
>> better than other methods?
> The fact that there is minimum hardware between the antenna and the transistors that measure voltage - I am also looking for macroscopic quantum effects.
> If you read voltage using an ADC with amplifiers, filtering, anti-aliassing etc you are bound to observe what the theory says is there, because that theory was used to design the system. I want to get closer to the hardware.
> Best regards,
> Howerd
What sample rate do you plan to use? I guess I'm curious about how you plan to proceed. I can't think of anything the GA144 can do that other ADC devices can't.
I quickly read about OAM after reading your first post and I don't think it is in defiance to existing theory. I think no one (or few until recently) bothered to look for it. If it can't be observed using scientific methods, then it won't be of much use in building transceivers.
BTW, the GA144 ADC has all the same limitations you mention above, if you think it gets around any of the above, check again. The issue with anti-aliasing is not eliminated, it is just addressed in the ADC method to some extent. If you read up you will find the GA144 ADC anti-alias functionality is pretty poor for most applications depending on the frequencies you wish to exclude and which you wish to include.
On Tuesday, October 9, 2012 11:08:34 PM UTC+2, rickman wrote:
> On 10/9/2012 4:21 PM, Howerd wrote:
> > On Tuesday, October 9, 2012 7:48:14 PM UTC+2, rickman wrote:
> >> On 10/8/2012 4:31 PM, Howerd wrote:
> >>> On Monday, October 8, 2012 1:31:55 AM UTC+2, rickman wrote:
> >>>> what do you think you could use this device for
> >>>> that would be a better implementation than other devices?
> >>> I intend to use the GA144 to interface to one or more antennas. I have a"gut feeeling"
> >> that if you remove all of the simplifying assumptions between
> >> electromagnetic radiation
> >> and software you might be able to find some new properties of both.
> >>> I am particularly interested in the orbital angular momentum ( OAM ) property of
> >> electromagnetic radiation - I want to go back to basics and see whether
> >> this can be
> >> measured easily with a GA144. I think the 6 GHz counter and VCO might be
> >> able to resolve
> >> OAM effects. We shall see...
> >>> Best regards,
> >>> Howerd
> >> OAM eh? What aspects of the GA144 will enable this to be measured
> >> better than other methods? The 5.6 GHz counter is just an ADC with a
> >> variable resolution vs. sample rate. There are lots of ADC available
> >> with very high sample rates and much better resolution.
> >> Rick
> > Hi Rick,
> >> OAM eh? What aspects of the GA144 will enable this to be measured
> >> better than other methods?
> > The fact that there is minimum hardware between the antenna and the transistors that measure voltage - I am also looking for macroscopic quantum effects.
> > If you read voltage using an ADC with amplifiers, filtering, anti-aliassing etc you are bound to observe what the theory says is there, because that theory was used to design the system. I want to get closer to the hardware.
> > Best regards,
> > Howerd
> What sample rate do you plan to use? I guess I'm curious about how you
> plan to proceed. I can't think of anything the GA144 can do that other
> ADC devices can't.
> I quickly read about OAM after reading your first post and I don't think
> it is in defiance to existing theory. I think no one (or few until
> recently) bothered to look for it. If it can't be observed using
> scientific methods, then it won't be of much use in building transceivers.
> BTW, the GA144 ADC has all the same limitations you mention above, if
> you think it gets around any of the above, check again. The issue with
> anti-aliasing is not eliminated, it is just addressed in the ADC method
> to some extent. If you read up you will find the GA144 ADC anti-alias
> functionality is pretty poor for most applications depending on the
> frequencies you wish to exclude and which you wish to include.
> Rick
> Rick
Hi Rick,
> What sample rate do you plan to use?
I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
> I quickly read about OAM after reading your first post and I don't think
> it is in defiance to existing theory.
Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
Very much existing theory.
The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
> The issue with anti-aliasing is not eliminated, it is just addressed > in the ADC method to some extent.
My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
>> What sample rate do you plan to use?
> I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
I'm not sure I follow that. How will you change your sample rate? BTW, unless I don't understand the why the ADC works, every time you read the ADC it stops the counter for a short time. Be aware of this as it may have an impact on your measurements if not accounted for.
>> I quickly read about OAM after reading your first post and I don't think
>> it is in defiance to existing theory.
> Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
> Very much existing theory.
> The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
I still don't see how the GA144 ADC is any different for this than any other ADC.
>> The issue with anti-aliasing is not eliminated, it is just addressed
>> in the ADC method to some extent.
> My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
Anti-aliasing is used to prevent signals above the Nyquist rate (1/2 your sample rate) from affecting your measurement of baseband signals. If you aren't sampling in the conventional sense, there is no need to anti-alias. But then I'm not clear what you *are* doing so I can't say for sure.
On Saturday, October 13, 2012 8:28:54 PM UTC+2, rickman wrote:
> On 10/13/2012 10:39 AM, Howerd wrote:
> > Hi Rick,
> >> What sample rate do you plan to use?
> > I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
> I'm not sure I follow that. How will you change your sample rate? BTW,
> unless I don't understand the why the ADC works, every time you read the
> ADC it stops the counter for a short time. Be aware of this as it may
> have an impact on your measurements if not accounted for.
> >> I quickly read about OAM after reading your first post and I don't think
> >> it is in defiance to existing theory.
> > Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
> > Very much existing theory.
> > The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
> I still don't see how the GA144 ADC is any different for this than any
> other ADC.
> >> The issue with anti-aliasing is not eliminated, it is just addressed
> >> in the ADC method to some extent.
> > My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> your sample rate) from affecting your measurement of baseband signals.
> If you aren't sampling in the conventional sense, there is no need to
> anti-alias. But then I'm not clear what you *are* doing so I can't say
> for sure.
> Rick
Hi Rick,
> every time you read the ADC it stops the counter for a short time
There is no ADC, just a fast counter clocked by a VCO.
> I still don't see how the GA144 ADC is any different for this than any
> other ADC.
Its no different to any other VCO and counter, but it is possible to pass the count value on to other cores to process, before passing it to the outside world. That and having five of these on each chip makes it very good for waht I want to do.
> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> your sample rate) from affecting your measurement of baseband signals.
If I run the VCO flat out at 5GHz, using it as a over-sampled one-bit ADC this should be OK for 10 MHZ signals. If this is possible, of course - I may need to drop it down to 2.5GHz.
> But then I'm not clear what you *are* doing so I can't say for sure.
Maybe you have guesed that I'm not clear how to achieve what I want ;-)
But my direction is clear : for each antenna measure the electrical signal on an input pin as using the minimum number of transistors possible. Look at what really goes on when electicity interacts with antennas. Play it by ear...
I would like to start by repeating Chuck's measurement of wire length by timing a pulse bouncing back from the end of the wire.
> On Saturday, October 13, 2012 8:28:54 PM UTC+2, rickman wrote:
>> On 10/13/2012 10:39 AM, Howerd wrote:
>>> Hi Rick,
>>>> What sample rate do you plan to use?
>>> I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
>> I'm not sure I follow that. How will you change your sample rate? BTW,
>> unless I don't understand the why the ADC works, every time you read the
>> ADC it stops the counter for a short time. Be aware of this as it may
>> have an impact on your measurements if not accounted for.
>>>> I quickly read about OAM after reading your first post and I don't think
>>>> it is in defiance to existing theory.
>>> Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
>>> Very much existing theory.
>>> The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
>> I still don't see how the GA144 ADC is any different for this than any
>> other ADC.
>>>> The issue with anti-aliasing is not eliminated, it is just addressed
>>>> in the ADC method to some extent.
>>> My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
>> your sample rate) from affecting your measurement of baseband signals.
>> If you aren't sampling in the conventional sense, there is no need to
>> anti-alias. But then I'm not clear what you *are* doing so I can't say
>> for sure.
>> Rick
> Hi Rick,
>> every time you read the ADC it stops the counter for a short time
> There is no ADC, just a fast counter clocked by a VCO.
And the name they give it is an "ADC". Analog in, Digital out...
>> I still don't see how the GA144 ADC is any different for this than any
>> other ADC.
> Its no different to any other VCO and counter, but it is possible to pass the count value on to other cores to process, before passing it to the outside world. That and having five of these on each chip makes it very good for waht I want to do.
The question is how will you make use of this data? If you aren't going to treat it as the digital equivalent of an analog waveform, just what is it?
>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
>> your sample rate) from affecting your measurement of baseband signals.
> If I run the VCO flat out at 5GHz, using it as a over-sampled one-bit ADC this should be OK for 10 MHZ signals. If this is possible, of course - I may need to drop it down to 2.5GHz.
This statement clearly shows you don't understand what a VCO is. You *don't* run the VCO "flat out". The frequency varies with the input voltage, the voltage you are trying to measure. The frequency varies with the input voltage and drives the counter. By reading the counter at known times you can subtract successive values getting the difference which corresponds to the average voltage in that time period. You can process the counter values as you wish, but the frequency of the VCO is not constant.
How do you think the VCO works? Or are you planning to drive the VCO with Vss? Then what do you do with the input voltage?
>> But then I'm not clear what you *are* doing so I can't say for sure.
> Maybe you have guesed that I'm not clear how to achieve what I want ;-)
> But my direction is clear : for each antenna measure the electrical signal on an input pin as using the minimum number of transistors possible. Look at what really goes on when electicity interacts with antennas. Play it by ear...
> I would like to start by repeating Chuck's measurement of wire length by timing a pulse bouncing back from the end of the wire.
Ok, that should be pretty simple, but make sure it is a long enough wire. The CPU is fast, but not that fast. The 700 MIPS number is a peak rate and you can't get too close to that with real code.
On Saturday, October 13, 2012 10:54:56 PM UTC+2, rickman wrote:
> On 10/13/2012 4:37 PM, Howerd wrote:
> > On Saturday, October 13, 2012 8:28:54 PM UTC+2, rickman wrote:
> >> On 10/13/2012 10:39 AM, Howerd wrote:
> >>> Hi Rick,
> >>>> What sample rate do you plan to use?
> >>> I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
> >> I'm not sure I follow that. How will you change your sample rate? BTW,
> >> unless I don't understand the why the ADC works, every time you read the
> >> ADC it stops the counter for a short time. Be aware of this as it may
> >> have an impact on your measurements if not accounted for.
> >>>> I quickly read about OAM after reading your first post and I don't think
> >>>> it is in defiance to existing theory.
> >>> Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
> >>> Very much existing theory.
> >>> The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
> >> I still don't see how the GA144 ADC is any different for this than any
> >> other ADC.
> >>>> The issue with anti-aliasing is not eliminated, it is just addressed
> >>>> in the ADC method to some extent.
> >>> My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
> >> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> >> your sample rate) from affecting your measurement of baseband signals.
> >> If you aren't sampling in the conventional sense, there is no need to
> >> anti-alias. But then I'm not clear what you *are* doing so I can't say
> >> for sure.
> >> Rick
> > Hi Rick,
> >> every time you read the ADC it stops the counter for a short time
> > There is no ADC, just a fast counter clocked by a VCO.
> And the name they give it is an "ADC". Analog in, Digital out...
> >> I still don't see how the GA144 ADC is any different for this than any
> >> other ADC.
> > Its no different to any other VCO and counter, but it is possible to pass the count value on to other cores to process, before passing it to the outside world. That and having five of these on each chip makes it very good for waht I want to do.
> The question is how will you make use of this data? If you aren't going
> to treat it as the digital equivalent of an analog waveform, just what
> is it?
> >> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> >> your sample rate) from affecting your measurement of baseband signals.
> > If I run the VCO flat out at 5GHz, using it as a over-sampled one-bit ADC this should be OK for 10 MHZ signals. If this is possible, of course - I may need to drop it down to 2.5GHz.
> This statement clearly shows you don't understand what a VCO is. You
> *don't* run the VCO "flat out". The frequency varies with the input
> voltage, the voltage you are trying to measure. The frequency varies
> with the input voltage and drives the counter. By reading the counter
> at known times you can subtract successive values getting the difference
> which corresponds to the average voltage in that time period. You can
> process the counter values as you wish, but the frequency of the VCO is
> not constant.
> How do you think the VCO works? Or are you planning to drive the VCO
> with Vss? Then what do you do with the input voltage?
> >> But then I'm not clear what you *are* doing so I can't say for sure.
> > Maybe you have guesed that I'm not clear how to achieve what I want ;-)
> > But my direction is clear : for each antenna measure the electrical signal on an input pin as using the minimum number of transistors possible. Look at what really goes on when electicity interacts with antennas. Play it by ear...
> > I would like to start by repeating Chuck's measurement of wire length by timing a pulse bouncing back from the end of the wire.
> Ok, that should be pretty simple, but make sure it is a long enough
> wire. The CPU is fast, but not that fast. The 700 MIPS number is a
> peak rate and you can't get too close to that with real code.
> Rick
Hi Rick,
> And the name they give it is an "ADC"
Yes, OK, I meant not a conventional ADC, i.e. not delta-sigma, successive approximation, integrating etc...
> The question is how will you make use of this data? If you aren't going
> to treat it as the digital equivalent of an analog waveform, just what
> is it?
I want to interact with RF electrical signals using Forth, the same way I do with any other piece of hardware. So I don't know what I will do with the data - it depends on what I find.
I am hoping it will be like firing up a new processor with Forth for the first time and probing its peripherals, checking what I see against the databook.
> This statement clearly shows you don't understand what a VCO is.
No, it shows that I did not express myself clearly ;-)
I will probably run the VCO with an input voltage very close to Vss, and just look at the bottom bit of the counter. This will give me a 1-bit ADC with a 5 GHz sampling rate, if you want to look at it that way.
I want to detect the smallest possible voltage and time variations, then average them over human-scale time periods. I'm also not interested in absolute values of either voltage or time, just deltas.
> The CPU is fast, but not that fast.
True, but its the VCO that determines the sampling rate - 5 GHz has a wavelength of 5.9 cm. 50 GHz would be better...
> On Saturday, October 13, 2012 10:54:56 PM UTC+2, rickman wrote:
>> On 10/13/2012 4:37 PM, Howerd wrote:
>>> On Saturday, October 13, 2012 8:28:54 PM UTC+2, rickman wrote:
>>>> On 10/13/2012 10:39 AM, Howerd wrote:
>>>>> Hi Rick,
>>>>>> What sample rate do you plan to use?
>>>>> I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
>>>> I'm not sure I follow that. How will you change your sample rate? BTW,
>>>> unless I don't understand the why the ADC works, every time you read the
>>>> ADC it stops the counter for a short time. Be aware of this as it may
>>>> have an impact on your measurements if not accounted for.
>>>>>> I quickly read about OAM after reading your first post and I don't think
>>>>>> it is in defiance to existing theory.
>>>>> Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
>>>>> Very much existing theory.
>>>>> The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
>>>> I still don't see how the GA144 ADC is any different for this than any
>>>> other ADC.
>>>>>> The issue with anti-aliasing is not eliminated, it is just addressed
>>>>>> in the ADC method to some extent.
>>>>> My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
>>>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
>>>> your sample rate) from affecting your measurement of baseband signals.
>>>> If you aren't sampling in the conventional sense, there is no need to
>>>> anti-alias. But then I'm not clear what you *are* doing so I can't say
>>>> for sure.
>>>> Rick
>>> Hi Rick,
>>>> every time you read the ADC it stops the counter for a short time
>>> There is no ADC, just a fast counter clocked by a VCO.
>> And the name they give it is an "ADC". Analog in, Digital out...
>>>> I still don't see how the GA144 ADC is any different for this than any
>>>> other ADC.
>>> Its no different to any other VCO and counter, but it is possible to pass the count value on to other cores to process, before passing it to the outside world. That and having five of these on each chip makes it very good for waht I want to do.
>> The question is how will you make use of this data? If you aren't going
>> to treat it as the digital equivalent of an analog waveform, just what
>> is it?
>>>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
>>>> your sample rate) from affecting your measurement of baseband signals.
>>> If I run the VCO flat out at 5GHz, using it as a over-sampled one-bit ADC this should be OK for 10 MHZ signals. If this is possible, of course - I may need to drop it down to 2.5GHz.
>> This statement clearly shows you don't understand what a VCO is. You
>> *don't* run the VCO "flat out". The frequency varies with the input
>> voltage, the voltage you are trying to measure. The frequency varies
>> with the input voltage and drives the counter. By reading the counter
>> at known times you can subtract successive values getting the difference
>> which corresponds to the average voltage in that time period. You can
>> process the counter values as you wish, but the frequency of the VCO is
>> not constant.
>> How do you think the VCO works? Or are you planning to drive the VCO
>> with Vss? Then what do you do with the input voltage?
>>>> But then I'm not clear what you *are* doing so I can't say for sure.
>>> Maybe you have guesed that I'm not clear how to achieve what I want ;-)
>>> But my direction is clear : for each antenna measure the electrical signal on an input pin as using the minimum number of transistors possible. Look at what really goes on when electicity interacts with antennas. Play it by ear...
>>> I would like to start by repeating Chuck's measurement of wire length by timing a pulse bouncing back from the end of the wire.
>> Ok, that should be pretty simple, but make sure it is a long enough
>> wire. The CPU is fast, but not that fast. The 700 MIPS number is a
>> peak rate and you can't get too close to that with real code.
>> Rick
> Hi Rick,
>> And the name they give it is an "ADC"
> Yes, OK, I meant not a conventional ADC, i.e. not delta-sigma, successive approximation, integrating etc...
>> The question is how will you make use of this data? If you aren't going
>> to treat it as the digital equivalent of an analog waveform, just what
>> is it?
> I want to interact with RF electrical signals using Forth, the same way I do with any other piece of hardware.
> So I don't know what I will do with the data - it depends on what I find.
> I am hoping it will be like firing up a new processor with Forth for the first time and probing its peripherals, checking what I see against the databook.
>> This statement clearly shows you don't understand what a VCO is.
> No, it shows that I did not express myself clearly ;-)
> I will probably run the VCO with an input voltage very close to Vss, and just look at the bottom bit of the counter. This will give me a 1-bit ADC with a 5 GHz sampling rate, if you want to look at it that way.
> I want to detect the smallest possible voltage and time variations, then average them over human-scale time periods. I'm also not interested in absolute values of either voltage or time, just deltas.
Then you are looking for resolution, not VCO speed. You can use the GA144 ADC for high resolution at very slow sample rates. But if you don't know what you are looking for, I'm not sure how you will know when you find it.
Many other ADCs will give you very high resolution as well.
>> The CPU is fast, but not that fast.
> True, but its the VCO that determines the sampling rate - 5 GHz has a wavelength of 5.9 cm. 50 GHz would be better...
The rate of the VCO is not the sample rate of the ADC. The VCO is analog at the interface to the input signal and the frequency is analog (continuously variable). It is the counter that is digital.
On Saturday, October 13, 2012 11:30:44 PM UTC+2, rickman wrote:
> On 10/13/2012 5:14 PM, Howerd wrote:
> > On Saturday, October 13, 2012 10:54:56 PM UTC+2, rickman wrote:
> >> On 10/13/2012 4:37 PM, Howerd wrote:
> >>> On Saturday, October 13, 2012 8:28:54 PM UTC+2, rickman wrote:
> >>>> On 10/13/2012 10:39 AM, Howerd wrote:
> >>>>> Hi Rick,
> >>>>>> What sample rate do you plan to use?
> >>>>> I'm not intending to use the VCO as a conventional ADC, just observe the count as the voltage changes, so the sample rate will vary with voltage. Alos, mostly I want to measure timings.
> >>>> I'm not sure I follow that. How will you change your sample rate? BTW,
> >>>> unless I don't understand the why the ADC works, every time you read the
> >>>> ADC it stops the counter for a short time. Be aware of this as it may
> >>>> have an impact on your measurements if not accounted for.
> >>>>>> I quickly read about OAM after reading your first post and I don't think
> >>>>>> it is in defiance to existing theory.
> >>>>> Yes, OAM is predicted by quantum mechanics, and was first observed in 1935 IIRC.
> >>>>> Very much existing theory.
> >>>>> The theory that I want to get away from is where it is assumed that an electric field can be approximated by a scalar voltage. This may require 2, 3 or 4 receiving antennas and a transmitting antenna - measuring all signals in a synchronised way.
> >>>> I still don't see how the GA144 ADC is any different for this than any
> >>>> other ADC.
> >>>>>> The issue with anti-aliasing is not eliminated, it is just addressed
> >>>>>> in the ADC method to some extent.
> >>>>> My plan is to make some measurements of timings on wires and antennas, present them on a PC using colorForth (booted from a USB stick using USBboot), then relate this to the theory... Anti-aliassing will no doubt come into this at some stage.
> >>>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> >>>> your sample rate) from affecting your measurement of baseband signals.
> >>>> If you aren't sampling in the conventional sense, there is no need to
> >>>> anti-alias. But then I'm not clear what you *are* doing so I can't say
> >>>> for sure.
> >>>> Rick
> >>> Hi Rick,
> >>>> every time you read the ADC it stops the counter for a short time
> >>> There is no ADC, just a fast counter clocked by a VCO.
> >> And the name they give it is an "ADC". Analog in, Digital out...
> >>>> I still don't see how the GA144 ADC is any different for this than any
> >>>> other ADC.
> >>> Its no different to any other VCO and counter, but it is possible to pass the count value on to other cores to process, before passing it to the outside world. That and having five of these on each chip makes it very good for waht I want to do.
> >> The question is how will you make use of this data? If you aren't going
> >> to treat it as the digital equivalent of an analog waveform, just what
> >> is it?
> >>>> Anti-aliasing is used to prevent signals above the Nyquist rate (1/2
> >>>> your sample rate) from affecting your measurement of baseband signals.
> >>> If I run the VCO flat out at 5GHz, using it as a over-sampled one-bit ADC this should be OK for 10 MHZ signals. If this is possible, of course - I may need to drop it down to 2.5GHz.
> >> This statement clearly shows you don't understand what a VCO is. You
> >> *don't* run the VCO "flat out". The frequency varies with the input
> >> voltage, the voltage you are trying to measure. The frequency varies
> >> with the input voltage and drives the counter. By reading the counter
> >> at known times you can subtract successive values getting the difference
> >> which corresponds to the average voltage in that time period. You can
> >> process the counter values as you wish, but the frequency of the VCO is
> >> not constant.
> >> How do you think the VCO works? Or are you planning to drive the VCO
> >> with Vss? Then what do you do with the input voltage?
> >>>> But then I'm not clear what you *are* doing so I can't say for sure.
> >>> Maybe you have guesed that I'm not clear how to achieve what I want ;-)
> >>> But my direction is clear : for each antenna measure the electrical signal on an input pin as using the minimum number of transistors possible. Look at what really goes on when electicity interacts with antennas. Play it by ear...
> >>> I would like to start by repeating Chuck's measurement of wire length by timing a pulse bouncing back from the end of the wire.
> >> Ok, that should be pretty simple, but make sure it is a long enough
> >> wire. The CPU is fast, but not that fast. The 700 MIPS number is a
> >> peak rate and you can't get too close to that with real code.
> >> Rick
> > Hi Rick,
> >> And the name they give it is an "ADC"
> > Yes, OK, I meant not a conventional ADC, i.e. not delta-sigma, successive approximation, integrating etc...
> >> The question is how will you make use of this data? If you aren't going
> >> to treat it as the digital equivalent of an analog waveform, just what
> >> is it?
> > I want to interact with RF electrical signals using Forth, the same way I do with any other piece of hardware.
> > So I don't know what I will do with the data - it depends on what I find.
> > I am hoping it will be like firing up a new processor with Forth for the first time and probing its peripherals, checking what I see against the databook.
> >> This statement clearly shows you don't understand what a VCO is.
> > No, it shows that I did not express myself clearly ;-)
> > I will probably run the VCO with an input voltage very close to Vss, and just look at the bottom bit of the counter. This will give me a 1-bit ADC with a 5 GHz sampling rate, if you want to look at it that way.
> > I want to detect the smallest possible voltage and time variations, then average them over human-scale time periods. I'm also not interested in absolute values of either voltage or time, just deltas.
> Then you are looking for resolution, not VCO speed. You can use the
> GA144 ADC for high resolution at very slow sample rates. But if you
> don't know what you are looking for, I'm not sure how you will know when
> you find it.
> Many other ADCs will give you very high resolution as well.
> >> The CPU is fast, but not that fast.
> > True, but its the VCO that determines the sampling rate - 5 GHz has a wavelength of 5.9 cm. 50 GHz would be better...
> The rate of the VCO is not the sample rate of the ADC. The VCO is
> analog at the interface to the input signal and the frequency is analog
> (continuously variable). It is the counter that is digital.
> Rick
Hi Rick,
> Then you are looking for resolution, not VCO speed.
I am looking for both - detection of very small signals and very small time intervals.
> Many other ADCs will give you very high resolution as well.
Digital resolution, yes, but analog resolution probably not.
> GA144 ADC for high resolution at very slow sample rates.
I think you are using "resolution" in two different ways - there is analog resolution ( ability to detect a given change in voltage ), and ADC resolution ( number of bits ).
> The rate of the VCO is not the sample rate of the ADC
It is if it is a 1-bit ADC, sort of.
Its the analog resolution that I am interested in. I presume that the GA144's VCO is just a handful of transistors, so the bottom bit of the VCO count represents some very small change in the charge at the input pin.
Only with the GA144 do I get very sensitive analog inputs together with some fast processing, plus a high level (eForth or polyForth) IDE, all on chip.
I think this is magic :-)
> On Saturday, October 13, 2012 11:30:44 PM UTC+2, rickman wrote:
> Hi Rick,
>> Then you are looking for resolution, not VCO speed.
> I am looking for both - detection of very small signals and very small time intervals.
In the GA144 the time interval will be determined by the CPU speed, I think the best you might get is around 10 ns, but I don't recall exactly, this might be for a clock timed loop that just takes the data and passes it on. At that speed you will only get 4.3 ENOB (effective number of bits) theoretical max. That's not very sensitive.
>> Many other ADCs will give you very high resolution as well.
> Digital resolution, yes, but analog resolution probably not.
Uh, yeah... right. It's time to learn about electronics. You can think that you are going to toss existing theory out the window, but this is not the area that needs to be reinvented in order to learn about... what was it you were exploring again?
>> GA144 ADC for high resolution at very slow sample rates.
> I think you are using "resolution" in two different ways - there is analog resolution ( ability to detect a given change in voltage ), and ADC resolution ( number of bits ).
Yes, they are related by the gain of your amplifiers... uh, if you had amplifiers. In the GA144 integrating ADC the analog resolution will be related to the sample rate... if you have a sample rate. The faster the sample rate the lower the analog resolution. The 4.3 bits I mention above are over the analog range of about 1.2 volts, this is not well defined in the data sheet, so I'm not certain what this range is. The ADC has a non-linear curve with more resolution in the center which is what I am assuming will be used. Trying to get the full analog range of 1.8 volts uses the compressed ranges near the limits with very low analog resolution.
The digital resolution is the number of bits. The analog resolution is the analog range divided by the number of bits. No magic, no new science to be invented. The two are directly connected. The only way to improve the analog resolution is to slow down the measurement to give longer integrations or to use an amplifier to get the same voltage range at the ADC input with a smaller range on the amplifier input.
>> The rate of the VCO is not the sample rate of the ADC
> It is if it is a 1-bit ADC, sort of.
Ok, you can go ahead and think of this as a 1 bit ADC but that buys you the worst possible resolution at the highest sample rate.
> Its the analog resolution that I am interested in. I presume that the GA144's VCO is just a handful of transistors, so the bottom bit of the VCO count represents some very small change in the charge at the input pin.
No, the counter bits do NOT correspond to anything at the input. The counter free runs at a rate between about 3.5 GHz and 5.5 GHz. The raw readings just keep incrementing and the absolute values mean nothing. You get an ADC reading by SUBTRACTING one reading from the next. This DIFFERENCE is proportional to the integral of the voltage at the input over the sample period.
Actually, the range of the VCO in the linear area is only about 1.3 or 1.4 GHz rather than the 2 GHz I used to calculate the ENOB. The frequency range is what determines the difference range and the ADC resolution.
> Only with the GA144 do I get very sensitive analog inputs together with some fast processing, plus a high level (eForth or polyForth) IDE, all on chip.
> I think this is magic :-)
Yes, I expect it must seem like magic... Or you could listen to people who don't see it as magic, but rather understand the details and can explain how it works as if it were engineering...
I'm pretty sure you won't see anything in your signals using the GA144 that you can't see as well if not better using other devices. For example, how well will your readings be time correlated using multiple ADCs in the GA144? I can't get an answer to questions like this. Or even how long the GA144 nodes take to come out of sleep when the input clock transitions. These are *very* important numbers when using the ADC for signal acquisition. Random delays here cause signal distortion/noise.
> > On Saturday, October 13, 2012 11:30:44 PM UTC+2, rickman wrote:
> > Hi Rick,
> >> Then you are looking for resolution, not VCO speed.
> > I am looking for both - detection of very small signals and very small time intervals.
> In the GA144 the time interval will be determined by the CPU speed, I
> think the best you might get is around 10 ns, but I don't recall
> exactly, this might be for a clock timed loop that just takes the data
> and passes it on. At that speed you will only get 4.3 ENOB (effective
> number of bits) theoretical max. That's not very sensitive.
> >> Many other ADCs will give you very high resolution as well.
> > Digital resolution, yes, but analog resolution probably not.
> Uh, yeah... right. It's time to learn about electronics. You can
> think that you are going to toss existing theory out the window, but
> this is not the area that needs to be reinvented in order to learn
> about... what was it you were exploring again?
> >> GA144 ADC for high resolution at very slow sample rates.
> > I think you are using "resolution" in two different ways - there is analog resolution ( ability to detect a given change in voltage ), and ADC resolution ( number of bits ).
> Yes, they are related by the gain of your amplifiers... uh, if you had
> amplifiers. In the GA144 integrating ADC the analog resolution will be
> related to the sample rate... if you have a sample rate. The faster
> the sample rate the lower the analog resolution. The 4.3 bits I mention
> above are over the analog range of about 1.2 volts, this is not well
> defined in the data sheet, so I'm not certain what this range is. The
> ADC has a non-linear curve with more resolution in the center which is
> what I am assuming will be used. Trying to get the full analog range of
> 1.8 volts uses the compressed ranges near the limits with very low
> analog resolution.
> The digital resolution is the number of bits. The analog resolution is
> the analog range divided by the number of bits. No magic, no new
> science to be invented. The two are directly connected. The only way
> to improve the analog resolution is to slow down the measurement to give
> longer integrations or to use an amplifier to get the same voltage range
> at the ADC input with a smaller range on the amplifier input.
> >> The rate of the VCO is not the sample rate of the ADC
> > It is if it is a 1-bit ADC, sort of.
> Ok, you can go ahead and think of this as a 1 bit ADC but that buys you
> the worst possible resolution at the highest sample rate.
> > Its the analog resolution that I am interested in. I presume that the GA144's VCO is just a handful of transistors, so the bottom bit of the VCO count represents some very small change in the charge at the input pin.
> No, the counter bits do NOT correspond to anything at the input. The
> counter free runs at a rate between about 3.5 GHz and 5.5 GHz. The raw
> readings just keep incrementing and the absolute values mean nothing.
> You get an ADC reading by SUBTRACTING one reading from the next. This
> DIFFERENCE is proportional to the integral of the voltage at the input
> over the sample period.
> Actually, the range of the VCO in the linear area is only about 1.3 or
> 1.4 GHz rather than the 2 GHz I used to calculate the ENOB. The
> frequency range is what determines the difference range and the ADC
> resolution.
> > Only with the GA144 do I get very sensitive analog inputs together with some fast processing, plus a high level (eForth or polyForth) IDE, all on chip.
> > I think this is magic :-)
> Yes, I expect it must seem like magic... Or you could listen to people
> who don't see it as magic, but rather understand the details and can
> explain how it works as if it were engineering...
> I'm pretty sure you won't see anything in your signals using the GA144
> that you can't see as well if not better using other devices. For
> example, how well will your readings be time correlated using multiple
> ADCs in the GA144? I can't get an answer to questions like this. Or
> even how long the GA144 nodes take to come out of sleep when the input
> clock transitions. These are *very* important numbers when using the
> ADC for signal acquisition. Random delays here cause signal
> distortion/noise.
> Rick
Hi Rick,
> You can think that you are going to toss existing theory out the window,...
Not at all - I am looking for observable effects predicted by existing
theory.
> The digital resolution is the number of bits.
Ageed.
> The analog resolution is the analog range divided by the number of bits.
Only in the most simplistic model, ignoring oversampling, compressed
sampling, and maybe some other effects.
What concerns me here is that you seem to have such confidence in your
theoretical models of what goes on in electronic circuits.
Surely any theory only covers the available data, and must be modified
when new data comes long that doesn't fit in.
I want to look for new data...
I think the discussion of the GA144's ADC is missing the point. Let me
try to explain by describing two circuits :
1. An antenna, RF amplifier, anti-aliassing filter, very fast ADC,
fast DSP. Say some electrons wander down the antenna - what does it
take to observe a change in the DSP's output?
2. An antenna connected to the VCO input of an F18. The VCO is
presumably very few FET's arranged to oscillate, clocking a line of
edge triggered flip-flops. Bit 0 of the counter is averaged at, say,
100 Mhz rate.
I predict that #2 would be more sensitive, i.e. it would take fewer
electrons to make a visible change. There is also significantly more
possibility of quantum coupling efects occuring over just a few
transistors than over circuit #1.
Also, if I do not find any interesting new effects using the GA144,
there is not much more to be done, besides going to a faster chip
process, since this looks to me like the absolute minimum number of
components to convert a signal at the antenna to something useable.
I have nothing against circuit #1 - it does exactly what it is
designed to do.
Here are some questions that might be answered experimentally by the
GA144 :
1. does electrical current flowing down a wire have oribital angular
momentum (OAM), and if so could this be useful?
2. if a radio wave containing OAM arrives at two antennas, can the OAM
be detected by two F18 VCO's ?
3. is it posible to demodulate RF signals using an GA144 by applying
simple fast algorithms?
> how well will your readings be time correlated using multiple ADCs in the GA144?
This interests me too. There are two F18's with analog pins next to
each other, so it would be possible to have one waiting for the other
with just the latching time of the ports between them. I would expect
jitter of around 10ns if the F18 cores are also doing something useful
with the data, but this is really just a guess.
> Or even how long the GA144 nodes take to come out of sleep when the input clock transitions.
As I understand this, the GA144 doesn't "go to sleep" - it is clocked
by receiving an instruction on one of its ports.
So no time at all.
The VCO-counting-ADC is free running, so any two would be independent.
You could synchronise reading them, but the read pulse would not be
connected to the VCO, so I would expect a lot of jitter. I think the
GA144's ADC's are good for audio maybe, but not for low jitter, high
speed, high resolution measurements.
In my experience, it is best never to use ADC's, but to convert the
signal you want to measure into a time period. The GA144 is good at
measuring time periods...
I'm sorry if this sounds like the classic Forth question and answer :
Q. how would you do X in Forth? A. don't do X, do Y.
> On Oct 15, 1:54 am, rickman<gnu...@gmail.com> wrote:
>> On 10/14/2012 5:00 AM, Howerd wrote:
>>> On Saturday, October 13, 2012 11:30:44 PM UTC+2, rickman wrote:
>>> Hi Rick,
>>>> Then you are looking for resolution, not VCO speed.
>>> I am looking for both - detection of very small signals and very small time intervals.
>> In the GA144 the time interval will be determined by the CPU speed, I
>> think the best you might get is around 10 ns, but I don't recall
>> exactly, this might be for a clock timed loop that just takes the data
>> and passes it on. At that speed you will only get 4.3 ENOB (effective
>> number of bits) theoretical max. That's not very sensitive.
>>>> Many other ADCs will give you very high resolution as well.
>>> Digital resolution, yes, but analog resolution probably not.
>> Uh, yeah... right. It's time to learn about electronics. You can
>> think that you are going to toss existing theory out the window, but
>> this is not the area that needs to be reinvented in order to learn
>> about... what was it you were exploring again?
>>>> GA144 ADC for high resolution at very slow sample rates.
>>> I think you are using "resolution" in two different ways - there is analog resolution ( ability to detect a given change in voltage ), and ADC resolution ( number of bits ).
>> Yes, they are related by the gain of your amplifiers... uh, if you had
>> amplifiers. In the GA144 integrating ADC the analog resolution will be
>> related to the sample rate... if you have a sample rate. The faster
>> the sample rate the lower the analog resolution. The 4.3 bits I mention
>> above are over the analog range of about 1.2 volts, this is not well
>> defined in the data sheet, so I'm not certain what this range is. The
>> ADC has a non-linear curve with more resolution in the center which is
>> what I am assuming will be used. Trying to get the full analog range of
>> 1.8 volts uses the compressed ranges near the limits with very low
>> analog resolution.
>> The digital resolution is the number of bits. The analog resolution is
>> the analog range divided by the number of bits. No magic, no new
>> science to be invented. The two are directly connected. The only way
>> to improve the analog resolution is to slow down the measurement to give
>> longer integrations or to use an amplifier to get the same voltage range
>> at the ADC input with a smaller range on the amplifier input.
>>>> The rate of the VCO is not the sample rate of the ADC
>>> It is if it is a 1-bit ADC, sort of.
>> Ok, you can go ahead and think of this as a 1 bit ADC but that buys you
>> the worst possible resolution at the highest sample rate.
>>> Its the analog resolution that I am interested in. I presume that the GA144's VCO is just a handful of transistors, so the bottom bit of the VCO count represents some very small change in the charge at the input pin.
>> No, the counter bits do NOT correspond to anything at the input. The
>> counter free runs at a rate between about 3.5 GHz and 5.5 GHz. The raw
>> readings just keep incrementing and the absolute values mean nothing.
>> You get an ADC reading by SUBTRACTING one reading from the next. This
>> DIFFERENCE is proportional to the integral of the voltage at the input
>> over the sample period.
>> Actually, the range of the VCO in the linear area is only about 1.3 or
>> 1.4 GHz rather than the 2 GHz I used to calculate the ENOB. The
>> frequency range is what determines the difference range and the ADC
>> resolution.
>>> Only with the GA144 do I get very sensitive analog inputs together with some fast processing, plus a high level (eForth or polyForth) IDE, all on chip.
>>> I think this is magic :-)
>> Yes, I expect it must seem like magic... Or you could listen to people
>> who don't see it as magic, but rather understand the details and can
>> explain how it works as if it were engineering...
>> I'm pretty sure you won't see anything in your signals using the GA144
>> that you can't see as well if not better using other devices. For
>> example, how well will your readings be time correlated using multiple
>> ADCs in the GA144? I can't get an answer to questions like this. Or
>> even how long the GA144 nodes take to come out of sleep when the input
>> clock transitions. These are *very* important numbers when using the
>> ADC for signal acquisition. Random delays here cause signal
>> distortion/noise.
>> Rick
> Hi Rick,
>> You can think that you are going to toss existing theory out the window,...
> Not at all - I am looking for observable effects predicted by existing
> theory.
Then why do you need to use something that you feel will uncover things that haven't been seen before? If it fits in with existing theory, then it should be observable with existing technology.
>> The digital resolution is the number of bits.
> Ageed.
>> The analog resolution is the analog range divided by the number of bits.
> Only in the most simplistic model, ignoring oversampling, compressed
> sampling, and maybe some other effects.
> What concerns me here is that you seem to have such confidence in your
> theoretical models of what goes on in electronic circuits.
> Surely any theory only covers the available data, and must be modified
> when new data comes long that doesn't fit in.
> I want to look for new data...
That's fine, but my point is that you have said nothing understandable that indicates the GA144 will do anything any other ADC can't do. You talk about 5 GHz as if it is the sample rate and it isn't, you talk about the counter lsb as if this is somehow related to a very low sensitivity voltage and it isn't. Before you can even make a measurement with the GA144 ADC you need to understand how it works and how it doesn't work.
> I think the discussion of the GA144's ADC is missing the point. Let me
> try to explain by describing two circuits :
> 1. An antenna, RF amplifier, anti-aliassing filter, very fast ADC,
> fast DSP. Say some electrons wander down the antenna - what does it
> take to observe a change in the DSP's output?
Your use of "DSP's output" is not clear. Do you mean the ADC output? To see a change you need enough voltage at the input to the ADC to cross one of the many thresholds in the ADC. This will of course on the voltage change at the antenna, the characteristics of the filter and the gain of the amplifier.
> 2. An antenna connected to the VCO input of an F18. The VCO is
> presumably very few FET's arranged to oscillate, clocking a line of
> edge triggered flip-flops. Bit 0 of the counter is averaged at, say,
> 100 Mhz rate.
This made sense until you talk about bit 0 "averaged at" 100 MHz. I don't know what that means. The frequency of the VCO output will vary between the values I listed the other day. Bit 0 will toggle at half that rate. Of course, this rate varies with the voltage of the input signal.
> I predict that #2 would be more sensitive, i.e. it would take fewer
> electrons to make a visible change. There is also significantly more
> possibility of quantum coupling efects occuring over just a few
> transistors than over circuit #1.
Quantum coupling to what? How will the VCO frequency change with quantum coupling? What in the GA144 will let you detect quantum coupling if it does happen? I don't recall a quantum coupling detector listed in the data sheet.
I don't see how the GA144 is any more sensitive to the antenna signal than the GA144. In fact the GA144 can be fairly insensitive depending on the sample rate. At high sample rates it is very insensitive.
> Also, if I do not find any interesting new effects using the GA144,
> there is not much more to be done, besides going to a faster chip
> process, since this looks to me like the absolute minimum number of
> components to convert a signal at the antenna to something useable.
> I have nothing against circuit #1 - it does exactly what it is
> designed to do.
> Here are some questions that might be answered experimentally by the
> GA144 :
> 1. does electrical current flowing down a wire have oribital angular
> momentum (OAM), and if so could this be useful?
If you are going to measure this, you need to predict outcomes. What will be observed if you do detect OAM? What will be observed if you don't detect OAM? Until you can answer that question there is no experiment really.
> 2. if a radio wave containing OAM arrives at two antennas, can the OAM
> be detected by two F18 VCO's ?
I give up, can it?
> 3. is it posible to demodulate RF signals using an GA144 by applying
> simple fast algorithms?
I can answer this one, yes. Just like you can demodulate RF signals using simple, fast algorithms on any other processor.
>> how well will your readings be time correlated using multiple ADCs in the GA144?
> This interests me too. There are two F18's with analog pins next to
> each other, so it would be possible to have one waiting for the other
> with just the latching time of the ports between them. I would expect
> jitter of around 10ns if the F18 cores are also doing something useful
> with the data, but this is really just a guess.
10 ns is a long time in the RF world. If you sample a 100 MHz carrier (middle of the FM band) this is an entire cycle of the carrier, 360 degrees, 2 pi radians, lots of confusion possible here.
Some folks posting here who worked with GA claim there can be low double digit ps of uncertainty in the sampling time, but I think this depends on a great many factors and I can't get answers out of GA to confirm any of it.
> > On Oct 15, 1:54 am, rickman<gnu...@gmail.com> wrote:
> >> On 10/14/2012 5:00 AM, Howerd wrote:
> >>> On Saturday, October 13, 2012 11:30:44 PM UTC+2, rickman wrote:
> >>> Hi Rick,
> >>>> Then you are looking for resolution, not VCO speed.
> >>> I am looking for both - detection of very small signals and very small time intervals.
> >> In the GA144 the time interval will be determined by the CPU speed, I
> >> think the best you might get is around 10 ns, but I don't recall
> >> exactly, this might be for a clock timed loop that just takes the data
> >> and passes it on. At that speed you will only get 4.3 ENOB (effective
> >> number of bits) theoretical max. That's not very sensitive.
> >>>> Many other ADCs will give you very high resolution as well.
> >>> Digital resolution, yes, but analog resolution probably not.
> >> Uh, yeah... right. It's time to learn about electronics. You can
> >> think that you are going to toss existing theory out the window, but
> >> this is not the area that needs to be reinvented in order to learn
> >> about... what was it you were exploring again?
> >>>> GA144 ADC for high resolution at very slow sample rates.
> >>> I think you are using "resolution" in two different ways - there is analog resolution ( ability to detect a given change in voltage ), and ADC resolution ( number of bits ).
> >> Yes, they are related by the gain of your amplifiers... uh, if you had
> >> amplifiers. In the GA144 integrating ADC the analog resolution will be
> >> related to the sample rate... if you have a sample rate. The faster
> >> the sample rate the lower the analog resolution. The 4.3 bits I mention
> >> above are over the analog range of about 1.2 volts, this is not well
> >> defined in the data sheet, so I'm not certain what this range is. The
> >> ADC has a non-linear curve with more resolution in the center which is
> >> what I am assuming will be used. Trying to get the full analog range of
> >> 1.8 volts uses the compressed ranges near the limits with very low
> >> analog resolution.
> >> The digital resolution is the number of bits. The analog resolution is
> >> the analog range divided by the number of bits. No magic, no new
> >> science to be invented. The two are directly connected. The only way
> >> to improve the analog resolution is to slow down the measurement to give
> >> longer integrations or to use an amplifier to get the same voltage range
> >> at the ADC input with a smaller range on the amplifier input.
> >>>> The rate of the VCO is not the sample rate of the ADC
> >>> It is if it is a 1-bit ADC, sort of.
> >> Ok, you can go ahead and think of this as a 1 bit ADC but that buys you
> >> the worst possible resolution at the highest sample rate.
> >>> Its the analog resolution that I am interested in. I presume that the GA144's VCO is just a handful of transistors, so the bottom bit of the VCO count represents some very small change in the charge at the input pin.
> >> No, the counter bits do NOT correspond to anything at the input. The
> >> counter free runs at a rate between about 3.5 GHz and 5.5 GHz. The raw
> >> readings just keep incrementing and the absolute values mean nothing.
> >> You get an ADC reading by SUBTRACTING one reading from the next. This
> >> DIFFERENCE is proportional to the integral of the voltage at the input
> >> over the sample period.
> >> Actually, the range of the VCO in the linear area is only about 1.3 or
> >> 1.4 GHz rather than the 2 GHz I used to calculate the ENOB. The
> >> frequency range is what determines the difference range and the ADC
> >> resolution.
> >>> Only with the GA144 do I get very sensitive analog inputs together with some fast processing, plus a high level (eForth or polyForth) IDE, all on chip.
> >>> I think this is magic :-)
> >> Yes, I expect it must seem like magic... Or you could listen to people
> >> who don't see it as magic, but rather understand the details and can
> >> explain how it works as if it were engineering...
> >> I'm pretty sure you won't see anything in your signals using the GA144
> >> that you can't see as well if not better using other devices. For
> >> example, how well will your readings be time correlated using multiple
> >> ADCs in the GA144? I can't get an answer to questions like this. Or
> >> even how long the GA144 nodes take to come out of sleep when the input
> >> clock transitions. These are *very* important numbers when using the
> >> ADC for signal acquisition. Random delays here cause signal
> >> distortion/noise.
> >> Rick
> > Hi Rick,
> >> You can think that you are going to toss existing theory out the window,...
> > Not at all - I am looking for observable effects predicted by existing
> > theory.
> Then why do you need to use something that you feel will uncover things
> that haven't been seen before? If it fits in with existing theory, then
> it should be observable with existing technology.
> >> The digital resolution is the number of bits.
> > Ageed.
> >> The analog resolution is the analog range divided by the number of bits.
> > Only in the most simplistic model, ignoring oversampling, compressed
> > sampling, and maybe some other effects.
> > What concerns me here is that you seem to have such confidence in your
> > theoretical models of what goes on in electronic circuits.
> > Surely any theory only covers the available data, and must be modified
> > when new data comes long that doesn't fit in.
> > I want to look for new data...
> That's fine, but my point is that you have said nothing understandable
> that indicates the GA144 will do anything any other ADC can't do. You
> talk about 5 GHz as if it is the sample rate and it isn't, you talk
> about the counter lsb as if this is somehow related to a very low
> sensitivity voltage and it isn't. Before you can even make a
> measurement with the GA144 ADC you need to understand how it works and
> how it doesn't work.
> > I think the discussion of the GA144's ADC is missing the point. Let me
> > try to explain by describing two circuits :
> > 1. An antenna, RF amplifier, anti-aliassing filter, very fast ADC,
> > fast DSP. Say some electrons wander down the antenna - what does it
> > take to observe a change in the DSP's output?
> Your use of "DSP's output" is not clear. Do you mean the ADC output?
> To see a change you need enough voltage at the input to the ADC to cross
> one of the many thresholds in the ADC. This will of course on the
> voltage change at the antenna, the characteristics of the filter and the
> gain of the amplifier.
> > 2. An antenna connected to the VCO input of an F18. The VCO is
> > presumably very few FET's arranged to oscillate, clocking a line of
> > edge triggered flip-flops. Bit 0 of the counter is averaged at, say,
> > 100 Mhz rate.
> This made sense until you talk about bit 0 "averaged at" 100 MHz. I
> don't know what that means. The frequency of the VCO output will vary
> between the values I listed the other day. Bit 0 will toggle at half
> that rate. Of course, this rate varies with the voltage of the input
> signal.
> > I predict that #2 would be more sensitive, i.e. it would take fewer
> > electrons to make a visible change. There is also significantly more
> > possibility of quantum coupling efects occuring over just a few
> > transistors than over circuit #1.
> Quantum coupling to what? How will the VCO frequency change with
> quantum coupling? What in the GA144 will let you detect quantum
> coupling if it does happen? I don't recall a quantum coupling detector
> listed in the data sheet.
> I don't see how the GA144 is any more sensitive to the antenna signal
> than the GA144. In fact the GA144 can be fairly insensitive depending
> on the sample rate. At high sample rates it is very insensitive.
> > Also, if I do not find any interesting new effects using the GA144,
> > there is not much more to be done, besides going to a faster chip
> > process, since this looks to me like the absolute minimum number of
> > components to convert a signal at the antenna to something useable.
> > I have nothing against circuit #1 - it does exactly what it is
> > designed to do.
> > Here are some questions that might be answered experimentally by the
> > GA144 :
> > 1. does electrical current flowing down a wire have oribital angular
> > momentum (OAM), and if so could this be useful?
> If you are going to measure this, you need to predict outcomes. What
> will be observed if you do detect OAM? What will be observed if you
> don't detect OAM? Until you can answer that question there is no
> experiment really.
> > 2. if a radio wave containing OAM arrives at two antennas, can the OAM
> > be detected by two F18 VCO's ?
> I give up, can it?
> > 3. is it posible to demodulate RF signals using an GA144 by applying
> > simple fast algorithms?
> I can answer this one, yes. Just like you can demodulate RF signals
> using simple, fast algorithms on any other processor.
> >> how well will your readings be time correlated using multiple ADCs in the GA144?
> > This interests me too. There are two F18's with analog pins next to
> > each other, so it would be possible to have one waiting for the other
> > with just the latching time of the ports between them. I would expect
> > jitter of around 10ns if the F18 cores are also doing something useful
> > with the data, but this is really just a guess.
> 10 ns is a long time in the RF world. If you sample a 100 MHz carrier
> (middle of the FM band) this is an entire cycle of the carrier, 360
> degrees, 2 pi radians,
> On Oct 15, 10:38 pm, rickman<gnu...@gmail.com> wrote:
> Hi Rick,
>> If it fits in with existing theory, then it should be observable with existing technology.
> Yes, the GA144 is existing technology...
That is not sufficient. There is a world of existing technology and some will do the job and some won't. The point is... and I'm getting really tired of trying to make it, if the stuff you want to measure fits existing theory then the existing technology that also fits that theory should be capable of measuring it. By existing technology I mean any ADC that has adequate resolution and speed.
>> you have said nothing understandable that indicates the GA144 will do anything any other ADC can't do.
> The GA144 is very simple, so the electrical path between input pin and
> counter output is very short.
> This might allow effects to be observed that would be smoothed out by
> amplifiers, filters and conventional ADCs.
But you don't have any idea that I can tell of what you are looking for. You never answered my question about what two outcomes would show the existence or absence of the effect you want to measure.
>> You talk about 5 GHz as if it is the sample rate and it isn't,
> If you clock a counter at 5GHz +/-100MHz, as the frequency changes the
> value of bit 0 of the counter when observed every 10 ns will change,
> and this value, if summed over a long period of time, will reflect the
> change in frequency. Since this is a VCO a small change in voltage
> will cause a small change in frequency which will cause a change in
> the summed count value.
Why do you need to look at this one bit? To detect the change in frequency over a long period you can just directly read the *entire* counter and subtract subsequent readings. This value is directly proportional to the frequency. The longer the period you monitor it the greater the analog resolution. I'm not sure dealing with bit 0 the way you describe will even give you a meaningful value. I believe you will simply be monitoring what amounts to aliasing.
> It depends on exactly how you define these terms, but you could view
> this as an oversampled 1 bit ADC - I'm not sure whether the sample
> rate is 5GHz or 100 MHz.
It's not. The VCO won't run at 5 GHz unless your input voltage is very close to Vdd.
> Either way this is not important for my application, because I am not
> thinking of the VCO as an ADC.
I know, you aren't thinking of it as an ADC, but you are using it as an ADC.
>> you talk about the counter lsb as if this is somehow related to a very low
>> sensitivity voltage and it isn't.
> As explained above, a small change in the VCO frequency will be shown
> as a change in the summed counter value.
No, because the frequency shows up in the counter by taking the difference.
> The high digital resolution is because of the oversampling, and the
> high analog resolution is because of the summing ( or averaging ).
If you say so.
> I see it this way : the VCO is DC biassed to run at some frequency,
> say 1GHz, with a very small AC modulation applied to it ( from the
> antenna ).
Ok, now you are biasing the ADC input with the input superimposed.
> say the VCO runs between 1,000,000 Hz and 1,000,001 Hz as the AC
> signal changes ( a 1 part 10E9 change ).
> You read the VCO's counter every 10 ns, so you would see a count of
> 0 , 10 , 20 , 30 at the low frequency , with a missed count every
> 10E9 counts at the higher frequency. Average this over 1 second and
> you would see a change of 1 in the counter as the AC input changed
> ( 1,000,000 mod 2**18 or 1,000,001 mod 2** 18 ).
Ok, so now you are reading the entire counter, not just bit 0. At the higher frequency you won't see a missed count, you will see a count of N+1. This is how I am suggesting that you use the ADC as an ADC. By "average" I assume you mean integrate or "sum"? Average would loose data unless you use fractions and then it is really just the same as integrating with a wasteful division at the end.
> To express this in terms of ADC's, it is a 10 x oversampled 1 bit ADC,
> averaged over 1 second.
No, it is just the same ADC that is designed into the GA144 sampled very fast and then the differences added back together which is the same as just subtracting the first reading from the last.
> This has sacrificed analog range - you measure only deltas, but I am
> only interested in deltas.
That is how you use the ADC, take the delta of the counter readings. This gives you the integral of the voltage over the sample period.
> Given that you can display the change of 1 count on a PC screen, this
> means that you can detect a change on the input pin that causes a 1 in
> 10E9 change in frequency - this is the high analog sensitivity that I
> hope to see.
What voltage will result in the change of 1? That depends on the period over which you integrate, it has nothing to do with the bias you apply. In fact, if you look at the ADC input curve you will see that it is most sensitive at the mid range and by biasing it near Vdd you are in a very flat range with little sensitivity.
> The thing that makes the GA144 special is that the electrical circuit
> between input pin and counter is the smallest it could be, so there
> could be very small quantum effects that would probably not occur with
> a conventional ADC setup.
Please explain how these quantum effects will be observed? What difference will this make on your readings?
>> While it is waiting for the input transition it is "asleep".
> I understand sleep mode in terms of chips like the MSP430, where the
> system clock is slowed down or stopped, and it takes some time to get
> it back to full speed.
> In the case of the MSP430 the design has been cleverly optimised for
> fast wake-up ( 6 us IIRC ).
Not 6 us, any processor can start up in 6 us if you keep the oscillator running or use gates for the oscillator. The F18A stops to wait for an input and resumes in some time less than an instruction cycle. They won't tell me how much of the port read instruction executes before the sleep and how much happens after the sleep. But they tell me I am free to measure it for myself...
> Since the GA144 has no clock, it does not have a distinct sleep state,
> and therefore it has no wake up time.
That is your terminology. Sleep means it is doing nothing and the processor is doing nothing while it is waiting for an input transition. Call it a rose if that makes you feel better.
>>> In my experience, it is best never to use ADC's, but to convert the
>>> signal you want to measure into a time period.
>> Oh, do you have lots of experience with this?
> Yes - I have used time measurement in preference to voltage on many
> projects.
>> How does the GA144 measure time periods?
>> I think Chuck does it by tying the ADC input to Vdd which will run the VCO at max rate.
> Yes, that is my understanding too. Its just a fast counter. Is there
> any other way to measure time periods?
>> Notice that there is no input signal in this example.
>> Where would you connect your input signal?
> On a digital input of a neighbouring F18, so that it captures the VCO
> counter when the input changes state.
What is this input signal? I thought we were talking about the antenna?
>> I thought you were interested in high resolution??? Now I'm very confused.
> I am interested in high resolution measurement of electrical charge
> flowing into the analog input pin.
> I think all this talk about ADC specs is confusing in this context...
No, what is confusing is that you won't talk about the ADC as an ADC. To measure electrical charge flowing (otherwise known as current) you need to add a resistor to turn the current into a voltage. Then the ADC can measure the voltage.
>> I'm still confused, what is X again?
> X is " how can I use the GA144's VCO as a very high resolution ADC?"
> Answer - you can't.
> Y is " how can I use the GA144's VCO to measure very small analog
> changes on its input pin with very high resolution?" Answer - see
> above.
Ok, now I understand. You don't want to measure voltage, charge *or* current, you want to measure ANALOG. I can see why you don't want to use an ANALOG to DIGITAL converter to measure ANALOGs. That would be pointless. BTW, perhaps you should share with the Green Arrays people that their ADC can't measure with high resolution. It will be news to them!!!
> I have found this thread very helpful, as it has forced me to organise
> and express my thoughts about what I would like to do with the GA144.
> Hopefully I will find some time soon to actually do these tests - I
> will report any results here :-)
Please keep us informed. I am finding this very entertaining... sort of.
I've chopped the bulk of the reply post because it is getting way too
long...
>> X is " how can I use the GA144's VCO as a very high resolution ADC?"
> BTW, perhaps you should share with the Green Arrays people
> that their ADC can't measure with high resolution.
No, you can't use the VCO as a VERY high resolution ADC ( 30 bits ).
But you can, I think, use it to measure down to this level if you use
the counter directly, and not as a conventional ADC.
> You don't want to measure voltage, charge *or* current, you want to measure ANALOG.
Exactly. Voltage and current are scalar quantities, quantum mechanics
shows that electric fields are vectors, so current flowing in a wire
is a 1 dimensional representation of a 2 or more dimensional field.
If you measure voltage with chips that are desinged to measure
voltage, you will only see voltage.
So, yes I want to measure ANALOG, whtever that is.
> I've chopped the bulk of the reply post because it is getting way too
> long...
>>> X is " how can I use the GA144's VCO as a very high resolution ADC?"
>> BTW, perhaps you should share with the Green Arrays people
>> that their ADC can't measure with high resolution.
> No, you can't use the VCO as a VERY high resolution ADC ( 30 bits ).
> But you can, I think, use it to measure down to this level if you use
> the counter directly, and not as a conventional ADC.
I think you need to read a bit more about the GA144 and how the ADC works. There is no limit to the resolution of the ADC data word. Once you actually understand how the ADC works, you will see that. But as long as you keep talking about the constituent parts, you will not see it.
>> You don't want to measure voltage, charge *or* current, you want to measure ANALOG.
> Exactly. Voltage and current are scalar quantities, quantum mechanics
> shows that electric fields are vectors, so current flowing in a wire
> is a 1 dimensional representation of a 2 or more dimensional field.
> If you measure voltage with chips that are desinged to measure
> voltage, you will only see voltage.
> So, yes I want to measure ANALOG, whtever that is.
Hey, ANALOG is *your* term, not mine! Go back to your previous post, you said, "Y is " how can I use the GA144's VCO to measure very small analog changes on its input pin with very high resolution?" Answer - see
above." So what is an ANALOG that you are measuring changes in?
> > I've chopped the bulk of the reply post because it is getting way too
> > long...
> >>> X is " how can I use the GA144's VCO as a very high resolution ADC?"
> >> BTW, perhaps you should share with the Green Arrays people
> >> that their ADC can't measure with high resolution.
> > No, you can't use the VCO as a VERY high resolution ADC ( 30 bits ).
> > But you can, I think, use it to measure down to this level if you use
> > the counter directly, and not as a conventional ADC.
> I think you need to read a bit more about the GA144 and how the ADC
> works. There is no limit to the resolution of the ADC data word. Once
> you actually understand how the ADC works, you will see that. But as
> long as you keep talking about the constituent parts, you will not see it.
> >> You don't want to measure voltage, charge *or* current, you want to measure ANALOG.
> > Exactly. Voltage and current are scalar quantities, quantum mechanics
> > shows that electric fields are vectors, so current flowing in a wire
> > is a 1 dimensional representation of a 2 or more dimensional field.
> > If you measure voltage with chips that are desinged to measure
> > voltage, you will only see voltage.
> > So, yes I want to measure ANALOG, whtever that is.
> Hey, ANALOG is *your* term, not mine! Go back to your previous post,
> you said, "Y is " how can I use the GA144's VCO to measure very small
> analog changes on its input pin with very high resolution?" Answer - see
> above." So what is an ANALOG that you are measuring changes in?
> Rick
Hi Rick,
> I think you need to read a bit more about the GA144 and how the ADC works.
Ah, the RTFM principle ;-)
> So what is an ANALOG that you are measuring changes in?
If I knew that, I wouldn't need to do the experiment.
Almost every mobile phone these days has a "chip antenna" - a small
block that picks up the RF. I don't know how these work, but they are
certainly not half wavelength dipoles. So there are some interesting
new developments in antenna technology that do not fit with my 1973-76
physics course.
I am curious what other possibilites exist, and the GA144 seems to be
an ideal chip experimenting with.
I want to get away from the (very useful) abstractions that are taught
in schools and get back to the simplest possible model that actually
fits the observations.
I'm not sure what was wrong, but it appears that I replied to an old message. Sorry if my reply sounded a bit cranky. It is just that much of this has gotten to be repetitive so I couldn't tell it was an old message, oddly enough.
> I'm not sure what was wrong, but it appears that I replied to an old
> message. Sorry if my reply sounded a bit cranky. It is just that much of
> this has gotten to be repetitive so I couldn't tell it was an old
> message, oddly enough.
> Rick
No, I was right the first time. For some odd reason the newsreader is showing my reply (the first one) as to an old message. But it was the most recent message I was responding to and it is highly repetitive with the rest of this conversation.
I've chopped the original text here, again because its is getting too long...
>:PhD? Hardly! A PhD dissertation is supposed to be about original
>work, not the mere implementation of a standard protocol.
Since no one has implemented USB on a GA144 I think this counts as original.
My point about making a good PhD thesis is that it needs a substantial amount of time, such a PhD thesis could provide.
> "Wait, do you feel that, a disturbance in the force? It must be the GA144!"
I would describe it more as a feeling of excitement - something new, created out of a desire for simplicity. The chip layout was designed using OKAD2 in colorForth. The architecture of each F18 is a very well thought out Forth machine.
The GA144 has just enough hard-coded interfaces that it can boot, and uses a power efficient, asynchronous design.
Each F18 has a built in BIOS to allow it to communicate with all the other F18's. This has effectively extended Forth into the world of parallel computing.
If this was just talk and speculation I would be quite interested, but I have seen OKAD2 in action, and I have two GA144's on an eval board sitting on the shelf, waiting for me to find some free time... They are real and they work :-)
What's not to get excited about?
But of course YMMV - whatever floats your boat...
> What is the GA144 SERDES protocol? What is the maximum rate,
> the minimum? What is the setup and hold timing on the data? BTW, it is
> *not* self-clocking. It has two wires,...
It sounds like 18 bit SPI to me. The data sheet says 450MHz.
You are right about the two wires though - I was confusing it with the 1-wire protocol which only runs at ~25MHz - only twice as fast as USB full speed.
> No, this is the absurdity of thinking you can design a
> useful chip and ignore the world it will be working in.
The alternative is to be a sheep and follow what every one else is doing.
> Yes, we have already discussed this and it is clear that the GA144 has
> no advantage over conventional ADCs for this app.
I think we will have to agree to differ on this.
> You also haven't said how OAM might manifest itself in a measurement,
> so you certainly can't say there is anything superior to any technique.
Not yet, clearly.
> More loony land stuff.
After all the GA144 looks like any other chip - its OK if you don't get excited about it ;-)
Its just from my eccentric perspective that the GA144 seems to be very special.
I got a similar feeling of excitement from the CDP1802 chip back in the late 70's - again something new and simple, and from seeing Forth for the first time, and colorForth etc. etc.
I usually pretend to be quite normal, except of course when there's a full moon ;-)
> I've chopped the original text here, again because its is getting too long...
>> :PhD? Hardly! A PhD dissertation is supposed to be about original
>> work, not the mere implementation of a standard protocol.
> Since no one has implemented USB on a GA144 I think this counts as original.
> My point about making a good PhD thesis is that it needs a substantial amount of time, such a PhD thesis could provide.
Yes, that is the problem. What should be a simple matter of implementing a standard protocol that runs on all sorts of processors down to small 8 bit MCUs, is instead a major exercise on the GA144.
The more I defend this device, the less I like it!
>> "Wait, do you feel that, a disturbance in the force? It must be the GA144!"
> I would describe it more as a feeling of excitement - something new, created out of a desire for simplicity.
> The chip layout was designed using OKAD2 in colorForth.
That's totally irrelevant.
> The architecture of each F18 is a very well thought out Forth machine.
"Well thought out" is a matter of opinion. Many here will disagree with you on that. I can think of a number of obvious functions missing from the GA144, the most significant is likely a real, clock based memory interface.
> The GA144 has just enough hard-coded interfaces that it can boot, and uses a power efficient, asynchronous design.
> Each F18 has a built in BIOS to allow it to communicate with all the other F18's. This has effectively extended Forth into the world of parallel computing.
That is what is missing. There is NO inter-CPU communications protocol built in. It was only a month or so ago that Chuck came up with an admittedly very complex scheme to pass data through nodes to get to a destination.
> If this was just talk and speculation I would be quite interested, but I have seen OKAD2 in action, and I have two GA144's on an eval board sitting on the shelf, waiting for me to find some free time... They are real and they work :-)
> What's not to get excited about?
> But of course YMMV - whatever floats your boat...
If I were designing chips I might get excited about OKAD. But I design boards and need chips that work and are well enough documented so that I can do my work.
>> What is the GA144 SERDES protocol? What is the maximum rate,
>> the minimum? What is the setup and hold timing on the data? BTW, it is
>> *not* self-clocking. It has two wires,...
> It sounds like 18 bit SPI to me. The data sheet says 450MHz.
> You are right about the two wires though - I was confusing it with the 1-wire protocol which only runs at ~25MHz - only twice as fast as USB full speed.
450 MHz is what, max, min, typ? How are words delineated? They may work, but what can they be used for?
>> No, this is the absurdity of thinking you can design a
>> useful chip and ignore the world it will be working in.
> The alternative is to be a sheep and follow what every one else is doing.
Yes, the sheep that design products that are bought and do useful stuff.
>> Yes, we have already discussed this and it is clear that the GA144 has
>> no advantage over conventional ADCs for this app.
> I think we will have to agree to differ on this.
If you could just explain anything about your ADC ideas that fits in with either the real design of the GA144 or electronics design I would be happy to just agree with you. But you have not answered any of my questions about how you will be using the ADCs.
>> You also haven't said how OAM might manifest itself in a measurement,
> That is because I don't know yet. Sorry.
> Apparently OAM is being used :
> http://www.extremetech.com/extreme/120803-vortex-radio-waves-could-bo... > although I am sceptical that you can even double the bandwidth using OAM in this way, due to increased noise. We shall see...
Yes, by people who understand OAM and also understand how ADCs work. Or do I misunderstand and they are all using GA144s in their receivers?
>> so you certainly can't say there is anything superior to any technique.
> Not yet, clearly.
>> More loony land stuff.
> After all the GA144 looks like any other chip - its OK if you don't get excited about it ;-)
> Its just from my eccentric perspective that the GA144 seems to be very special.
> I got a similar feeling of excitement from the CDP1802 chip back in the late 70's - again something new and simple, and from seeing Forth for the first time, and colorForth etc. etc.
> I usually pretend to be quite normal, except of course when there's a full moon ;-)
> Best regards,
> Howerd
Excited or irrational exuberance? I was impressed with the device at one point. Then I started to program with it and found the glaring lack of documentation combined with the resistance of the company to fill in the gaps. That, on top of the severe limitations of the chips. I do see the GA144 being useful in some limited applications, but the harder I look at it, the more limited these apps seem to be.
