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Re: GA144 use cases

From rickman <gnuarm@gmail.com>
Newsgroups comp.lang.forth
Subject Re: GA144 use cases
Date 2015-09-10 01:43 -0400
Organization A noiseless patient Spider
Message-ID <msr55v$tar$1@dont-email.me> (permalink)
References (7 earlier) <msq680$58i$1@dont-email.me> <8737ynt1b2.fsf@jester.gateway.pace.com> <msqu5c$bkr$1@dont-email.me> <msqvj6$d3i$3@dont-email.me> <66783d4e-9cff-49ca-b7ac-b59856d17ab3@googlegroups.com>

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On 9/10/2015 12:55 AM, Stefan Mauerhofer wrote:
> Since this post is about the GA144 I will post some (very short) code for this chip.
>
> Yes Rick, in the GA144 we have no time base whatsoever. The (almost) only thing we have that goes into this direction is a counted loop. The smallest loop for a F18A is "for unext". The unext instruction is in slot 0 and its execution time is around 2 ns. If we call the counted loop with a parameter n on top of the stack we have an delay of (n+1)*2 ns. The next longer counted loop is (n+1) with a delay of (n+2)*2 ns.
>
> So what can we do if we want a delay between these discrete points? We could alternate the loop values between n and n+1. If we feed the loop with an alternate sequence of values n n+1 (n n+1 n n+1 ...), then we get a average delay that is roughly (n + 1.5)*2 ns.
>
> If we want a higher resolution then we must enlarge the (n n+1) pattern. I am using a pattern of size 64. I could send 63 n and 1 n+1 value to the counted loop. This gives me a delay of (n + 1 + (1/64)) * 2 ns delay. If I send 62 n and 2 n+1 then the average delay is (n + 1 + (2/64)) * 2 ns. we could go on until we reach 1 n and 63 n+1 values (average delay of (n + 1 + (63/64)) * 2 ns. This is the basic mechanism to increase the time resolution of a counted loop.
>
> The Bresenham algorithm is used to distribute the n and n+1 values as evenly as possible.

I don't recall exactly the Bresenham algorithm, but I'd be willing to 
bet it ends up being the same as an NCO, numerically controlled 
oscillator.  The average frequency is the ratio of two integers, the 
step size and the counter modulus.  This is an often used algorithm for 
generating a frequency with as much precision as required.


> Starting a crystal means to pump energy into the crystal, thus converting electrical energy into mechanical energy. The energy is most easily transmitted if we pump the energy with the crystal's resonance frequency. If we don't hit the resonance frequency then our energy will dissipate and the crystal will not oscillate.

I seem to recall the info I read at GA on their oscillator attempt put 
out a ping, a minimum width impulse into the crystal.  That is likely 
more than enough for maintaining the energy in the crystal, but to start 
it a square wave might work better to put more energy in more quickly. 
Which did you do at the start?


> Since we don't know the exact delay of a unext loop, which is dependent of the voltage, temperature and chip fabrication, we must scan through a range of delay values until we hit the crystal's resonance frequency.

Do you stimulate the crystal for a fixed amount of time at a given 
frequency?  Or do you "look" for the crystal oscillating in response to 
your stimulus?  I guess it is likely both, stimulate for a time and then 
look.  If no input back from the crystal, move on to the next frequency. 
  What range of timing values do you cover?


> I hope this explains the method to start a 16 MHz crystal with a GA144.

Yes, this is as expected.  The interesting part will be to see how long 
it takes to get a crystal started in the worst case which is likely one 
or the other temperature extreme.

I know that many MCU makers don't specify their crystal oscillators very 
well.  I have had to ask manufacturers for more info which in one case 
found it's way into the data sheet.  The trick here will be to get well 
specified operation for specified crystals.  But then I am thinking like 
a potential GA customer and this is not being done by GA, but by you.

-- 

Rick

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GA144 use cases dunno <dunno@dunno.dunno> - 2015-08-31 07:20 +0000
  Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-08-31 09:55 -0400
  Re: GA144 use cases Syd Rumpo <usenet@nononono.co.uk> - 2015-08-31 16:49 +0100
    Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-08-31 18:35 -0400
  Re: GA144 use cases Dennis Ruffer <daruffer@gmail.com> - 2015-08-31 19:08 -0700
    Re: GA144 use cases Mux <Yvo.Zoer@gmail.com> - 2015-09-02 10:57 -0700
      Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 14:17 -0400
        Re: GA144 use cases Mux <Yvo.Zoer@gmail.com> - 2015-09-02 11:28 -0700
          Re: GA144 use cases hughaguilar96@gmail.com - 2015-09-02 13:41 -0700
          Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 16:50 -0400
            Re: GA144 use cases Mux <Yvo.Zoer@gmail.com> - 2015-09-02 15:03 -0700
              Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 18:18 -0400
                Re: GA144 use cases Mux <Yvo.Zoer@gmail.com> - 2015-09-02 16:14 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 20:40 -0400
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-02 17:53 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 21:25 -0400
                Re: GA144 use cases Mux <Yvo.Zoer@gmail.com> - 2015-09-02 22:28 -0700
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-02 22:53 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-03 11:32 -0400
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-03 11:57 -0700
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-03 10:35 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-03 15:54 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-03 16:11 +0000
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-03 13:06 -0400
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-04 08:07 +0000
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-04 11:49 -0400
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-05 11:06 +0000
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-05 09:05 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-05 12:59 -0400
                Re: GA144 use cases mhx@iae.nl - 2015-09-05 10:56 -0700
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-06 14:29 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-03 22:08 +0200
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-03 14:00 -0700
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-04 01:28 +0200
                Re: GA144 use cases franck.bensusan@gmail.com - 2015-09-03 23:04 -0700
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-04 08:24 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-04 15:09 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-05 15:10 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-05 22:04 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-06 14:51 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-06 22:51 +0200
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-06 17:30 -0700
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-04 22:27 -0700
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-05 13:07 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-05 11:22 +0000
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-04 08:14 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-04 15:13 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-05 16:06 +0000
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-05 21:05 +0200
                Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-06 14:37 +0000
                Re: GA144 use cases Andrew Haley <andrew29@littlepinkcloud.invalid> - 2015-11-30 04:17 -0600
                Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-12-01 23:06 +0100
                Re: GA144 use cases Mark Wills <markwills1970@gmail.com> - 2015-09-03 00:05 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-03 13:08 -0400
              Re: GA144 use cases forther <forther@gmail.com> - 2015-09-07 11:26 -0700
      Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-02 15:15 -0400
    Re: GA144 use cases forther <forther@gmail.com> - 2015-09-07 11:21 -0700
      Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-11-30 16:33 -0500
        Re: GA144 use cases forther <forther@gmail.com> - 2015-12-03 12:12 -0800
          Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-12-03 16:10 -0500
  Re: GA144 use cases Jason Damisch <jasondamisch@yahoo.com> - 2015-09-02 12:10 -0700
  Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-03 01:27 -0700
    Re: GA144 use cases Syd Rumpo <usenet@nononono.co.uk> - 2015-09-03 13:32 +0100
      Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-03 11:32 -0400
  Re: GA144 use cases mhx@iae.nl (Marcel Hendrix) - 2015-09-03 18:57 +0200
    Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-03 23:58 +0200
    Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-04 07:52 +0000
    Re: GA144 use cases Waldek Hebisch <hebisch@antispam.uni.wroc.pl> - 2015-09-05 16:32 +0000
      Re: GA144 use cases mhx@iae.nl - 2015-09-05 10:52 -0700
        Re: GA144 use cases Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-05 22:11 +0200
          Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-06 14:18 +0000
            Re: GA144 use cases anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-09-07 07:49 +0000
        Re: GA144 use cases Waldek Hebisch <hebisch@math.uni.wroc.pl> - 2015-09-05 23:42 +0000
          Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-05 17:25 -0700
  Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-07 03:18 -0700
    Re: GA144 use cases Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-09-07 03:31 -0700
      Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-07 15:06 -0400
        Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-08 21:41 -0700
          Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-09 02:54 -0400
            Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-09 03:02 -0700
              Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-09 16:55 -0400
                Re: GA144 use cases Paul Rubin <no.email@nospam.invalid> - 2015-09-09 20:12 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-09 23:40 -0400
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-09 23:43 -0400
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-10 00:07 -0400
                Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-09 21:55 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-10 01:43 -0400
                Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-09 23:49 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-10 14:43 -0400
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-10 16:10 -0400
                Re: GA144 use cases Stefan Mauerhofer <smauerhofer@androsoft.ch> - 2015-09-12 03:15 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-12 10:28 -0400
                Re: GA144 use cases Greg <abiforth@gmail.com> - 2015-09-13 13:05 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-13 18:59 -0400
                Re: GA144 use cases Greg <abiforth@gmail.com> - 2015-09-13 18:42 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-13 22:47 -0400
                Re: GA144 use cases Greg <abiforth@gmail.com> - 2015-09-13 21:24 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-14 02:00 -0400
                Re: GA144 use cases borota@gmail.com - 2015-09-14 08:35 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-14 12:06 -0400
                Re: GA144 use cases borota@gmail.com - 2015-09-14 09:33 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-14 13:25 -0400
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-14 14:17 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-14 18:12 -0400
                Re: GA144 use cases Greg <schmegner@gmail.com> - 2015-09-14 18:15 -0700
                Re: GA144 use cases rickman <gnuarm@gmail.com> - 2015-09-14 22:16 -0400
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-18 14:50 -0700
                Re: GA144 use cases Jason Damisch <jasondamisch@yahoo.com> - 2015-09-18 15:11 -0700
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-19 05:32 -0700
                Re: GA144 use cases Dennis Ruffer <daruffer@gmail.com> - 2015-09-19 08:39 -0700
                Re: GA144 use cases Greg <borota@gmail.com> - 2015-09-20 19:03 -0700
                Re: GA144 use cases Dennis Ruffer <daruffer@gmail.com> - 2015-09-21 06:44 -0700
                Re: GA144 use cases Dennis Ruffer <daruffer@gmail.com> - 2015-09-22 13:10 -0700
                Re: GA144 use cases Mark Wills <markwills1970@gmail.com> - 2015-09-18 16:18 -0700
                Re: GA144 use cases schmegner@gmail.com - 2015-09-14 18:21 -0700

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