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Re: ball-hours

Cross-posted to 2 groups.

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On 10/16/2014 2:21 PM, Joerg wrote:
> rickman wrote:
>> On 10/15/2014 7:12 PM, Joerg wrote:
>>> rickman wrote:
>>>> On 10/15/2014 8:36 AM, Joerg wrote:
>>>>> Problem is, there is no Forth community out here. The last die-hard
>>>>> Forth aficionado I personally met was about 30 years ago in Europe.
>>>>
>>>> I think you may be surprised.  I've already heard from three programmers
>>>> from the few posts I've made in just three groups.  Unless you want me
>>>> to send then directly to you, I am referring them to this thread.
>>>>
>>>
>>> One of them contacted me already. They are sort of local but not really
>>> local-local, like in the same village, down the road from here. We will
>>> have lots of situations such as "Hey, I got stuck with the test rig, can
>>> you come over real quick?" or "The relief valve over yonder blew a
>>> gasket, can you replace it?".
>>
>> So why aren't you working in the same lab?  Then it can be like,
>> "Watson, come here.  I want you".
>>
>
> Because as mentioned before if both are consultants it creates
> confidentiality issues. I have only one room (office plus lab) and
> another one mostly used for library and parts storage but not
> acoustically shielded. I often have to hop on GoTo or some other service
> to discuss another client's issue and then I must be alone. Sometimes
> for 1-2h. In contrast to contractors who work one longer assignment at a
> time I always have half a dozen or more active clients.
>
>
>> BTW, if you heard from Charley Shattuck, he is a prominent Forth
>> programmer.  He is working with a startup that developed a Forth like
>> CPU with 144 processors with a peak rate of 700 MIPS each.  This chip
>> includes 5 ADC and 5 DAC on chip with variable resolution (trade off
>> between speed and resolution, about 15 bits at 48 ksps).  You might talk
>> to him about the GA144, it might suit your needs.  It's main limitation
>> is each processor has little memory and the I/O is limited.  But I don't
>> think you will run out of MIPS.  lol
>>
>
> Yes, had an email exchange with Charley.
>
> 144 processors with 700MIPS each would probably require us to also build
> a nuclear power station :-) ... just kidding, I know it's green.

Each processor is very low power when running flat out, just 5 mW.  But 
they almost never run flat out.  Because they are asynchronous they 
spend most of their time stopped when they draw 0.0875 uW, yes, that's 
less than a tenth of a uW for each processor or just 12 uW for the whole 
chip.  The processors respond to stimuli in just nanoseconds, not 100's 
or even 10' but single digit nanoseconds.

Trust me, power will not be a problem with this part.  It is a very 
different beast to program however.


>>>>                                     ... Your other post seemed to be
>>>> talking about bitbanging the I2S port to the CODEC.  How does that work
>>>> into the 100 MHz need?  Bitbanging a serial port of any kind can be CPU
>>>> cycle intensive.
>>>>
>>>
>>> Yes, it is a major concern. We might need to hang an FPGA in there at
>>> least for TX, as a buffer, because essentially we are writing sine
>>> waves. Doesn't work on RX though, that's time-varying stuff. I hope I2S
>>> works for us, somehow. Got to find out.
>>
>> ???
>>
>
> Well, to send out sine waves. No need to necessarily bother a processor
> with that. Or I use a DDS but that can cost in clock synchronicity.

Every problem in your design is asking for an FPGA.


>> What are the specs you need from the ADC?  Do you have numbers and such?
>>   I think you mentioned a low drift with temperature.  The GA144 would
>> need to be compensated for temperature, but has lots of processing to do
>> that.  :)
>>
>
> Five needed in total, 18bits or more, 48ksps, differential inputs, BW
> from DC to 15kHz, without phase jitter issues. DC-Offset can be handled
> via mux and SW-clamping as long as it won't jitter or drift around much.

"phase jitter issues" and "won't jitter or drift around much" aren't 
specs.  18 bits of what exactly?  I have seen lots of devices with 24 
bits but only 96 dB SNR.  Do you need 108 dB SNR?  You won't get that 
from the GA144 ADCs at 48 kHz.

-- 

Rick

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Thread

Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 00:25 -0400
  Re: ball-hours bruce.person@gmail.com - 2014-10-14 23:51 -0700
    Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 03:15 -0400
  Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-15 05:36 -0700
    Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 16:22 -0400
      Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-15 16:12 -0700
        Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-15 22:48 -0400
          Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 11:21 -0700
            Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 15:24 -0400
              Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 13:37 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 17:42 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 07:14 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 14:03 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 12:03 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 15:23 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 12:44 -0700
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 18:37 -0400
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 20:59 -0400
                Re: ball-hours albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-17 08:43 +0000
                Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-17 13:53 -0400
                Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-17 07:50 -0700
        Re: ball-hours Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-10-15 20:42 -0700
          Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 01:50 -0400
            Re: ball-hours Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-10-16 00:49 -0700
              Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 05:14 -0400
            Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 11:58 -0700
        Re: ball-hours "Elizabeth D. Rather" <erather@forth.com> - 2014-10-16 08:32 -1000
          Re: ball-hours rickman <gnuarm@gmail.com> - 2014-10-16 15:32 -0400
          Re: ball-hours Joerg <news@analogconsultants.com> - 2014-10-16 13:45 -0700

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