Re: Forth CPUs with NO Interrupts

From	rickman <gnuarm@gmail.com>
Newsgroups	comp.lang.forth
Subject	Re: Forth CPUs with NO Interrupts
Date	2015-09-02 18:02 -0400
Organization	A noiseless patient Spider
Message-ID	<ms7riu$49n$1@dont-email.me> (permalink)
References	<mrjgkk$rde$1@dont-email.me> <4a53193d-9484-4de1-bfae-fc31def6e307@googlegroups.com> <2421d53e-a54b-4a33-beff-1d161f600b97@googlegroups.com> <ms0h3e$9vr$1@dont-email.me> <3f2923f8-6fc1-472c-9eb9-f33f5bf5c4ab@googlegroups.com>

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On 9/2/2015 5:14 PM, hughaguilar96@gmail.com wrote:
> On Sunday, August 30, 2015 at 8:20:59 PM UTC-7, rickman wrote:
>> On 8/30/2015 11:06 PM, hughaguilar96@gmail.com wrote:
>>> On Sunday, August 30, 2015 at 7:01:59 PM UTC-7, pbj...@gmail.com
>>> wrote:
>>>> Interrupts? ah fooie!
>>>
>>> I agree that having more than one processor makes things easier. The
>>> MiniForth had an 8032 on board with some 64MB of RAM (not a typo:
>>> 64MB not 64KB). The 8032 had a UART built in, which the MiniForth
>>> lacked, so the 8032 buffered the files from the desktop-computer and
>>> then fed the data to the MiniForth through parallel I/O --- this way
>>> the MiniForth could do the laser etching, but not have to store the
>>> big files in memory (it had limited memory) --- the timing was pretty
>>> precise on the motion-control, so you really can't have the processor
>>> interrupted by a UART while it is in the middle of etching.
>
>> It seems a bit odd to have the complexity of a CPU in an FPGA to handle
>> the relatively simple task of motion control.  Why not use a simpler CPU
>> like the 8032 to control dedicated hardware for motion control?  FPGAs
>> are all about application dedicated hardware.  Much easier to get the
>> synchronization and precise control that way.
>
> Rickman obviously has no experience with motion-control. This is actually a difficult task. The tool has to accelerate and decelerate smoothly. The goal is to minimize harmonic resonance. There is a lot of math involved. A lot of motion-control programs solve this problem simply by putting a big delay (like 20 milliseconds) between every change of direction for the tool. This can't be done in a laser-etcher however. The tool (a mirror that directs the laser beam down onto the work surface) has to move at a steady speed so the laser will burn into the surface to a steady depth and width. If there were variations in speed at the joints where the lines change direction, then the laser would burn a blotch into the work surface at those joints.
>
> Testra used an 80c320 originally, and over time they converted all of the Forth code into assembly-language. It was too slow however (mostly because 16-bit multiplication was slow) --- this is why the MiniForth was invented --- to be a replacement for the 80c320 providing better speed (note that the 80c320 is more than three times faster than the 8032 that Rickman recommends).
>
> I don't actually have any experience with motion-control. The entire time that I worked at Testra, I never saw the source-code for the motion-control program, as that was highly proprietary. All I did was write MFX, the development system for the MiniForth --- the motion-control program is the only program that has ever been written in MFX, and I didn't see the source-code --- at least I admit that I don't know anything about motion-control however, which is a lot different than Rickman who describes motion-control as a "relatively simple task" and yet knows less about the subject than I do.

No, I am not an expert in motion control.  My point was about the 
division of labor between the fast processor and the slow.  It seemed a 
bit odd to design a custom processor and then to program it in a custom 
language rather than to use an FPGA in the manner in which they work 
best.  Of course I don't know the details of this application.  That is 
why I *asked*.  I think the answer I got was a more rude version of, "I 
don't know."

Ok, I got it.

-- 

Rick

Thread

Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-26 00:53 -0400
  Re: Forth CPUs with NO Interrupts anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-08-26 08:51 +0000
    Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-26 08:50 -0400
    Re: Forth CPUs with NO Interrupts "Elizabeth D. Rather" <erather@forth.com> - 2015-08-26 07:23 -1000
  Re: Forth CPUs with NO Interrupts Mark Wills <markwills1970@gmail.com> - 2015-08-26 04:33 -0700
    Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-26 08:46 -0400
    Re: Forth CPUs with NO Interrupts mhx@iae.nl - 2015-08-26 11:17 -0700
    Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-08-26 12:50 -0700
      Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-26 18:28 -0400
    Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-08-27 23:44 -0700
      Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-08-28 18:28 -0700
  Re: Forth CPUs with NO Interrupts Walter Banks <walter@bytecraft.com> - 2015-08-26 11:41 -0400
  Re: Forth CPUs with NO Interrupts Syd Rumpo <usenet@nononono.co.uk> - 2015-08-26 17:12 +0100
    Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-08-26 09:48 -0700
    Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-26 18:39 -0400
  Re: Forth CPUs with NO Interrupts "Ala'a Alawi" <amalawi@gmail.com> - 2015-08-27 08:37 -0700
  Re: Forth CPUs with NO Interrupts pbjtech@gmail.com - 2015-08-30 19:01 -0700
    Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-30 22:45 -0400
      Re: Forth CPUs with NO Interrupts Reinhardt Behm <rbehm@hushmail.com> - 2015-08-31 11:09 +0800
    Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-08-30 20:06 -0700
      Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-08-30 23:20 -0400
        Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-09-02 14:14 -0700
          Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 18:02 -0400
      Re: Forth CPUs with NO Interrupts Bob <bob@none.com> - 2015-08-31 20:49 -0400
        Re: Forth CPUs with NO Interrupts Mark Wills <markwills1970@gmail.com> - 2015-09-01 01:39 -0700
          Re: Forth CPUs with NO Interrupts dunno <dunno@dunno.dunno> - 2015-09-01 17:58 +0000
          Re: Forth CPUs with NO Interrupts Bob <bob@none.com> - 2015-09-01 18:48 -0400
            Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-09-01 16:32 -0700
            Re: Forth CPUs with NO Interrupts Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-02 01:38 +0200
              Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-01 22:09 -0400
                Re: Forth CPUs with NO Interrupts Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-02 14:12 +0200
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 12:40 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-02 10:40 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 16:57 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-02 14:55 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 18:11 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-02 16:20 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 20:42 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-02 22:34 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-03 12:59 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-03 15:54 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-03 19:54 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-03 21:13 -0700
                Re: Forth CPUs with NO Interrupts Jan Coombs <Jan-54 <jenfhaomndgfwutc@murmic.plus.com>> - 2015-09-04 09:48 +0100
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-04 08:49 -0700
                Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-09-04 11:15 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-04 14:32 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-04 11:36 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-04 17:46 -0400
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-04 11:47 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-04 09:20 -0700
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-04 12:52 -0400
                Re: Forth CPUs with NO Interrupts Mux <Yvo.Zoer@gmail.com> - 2015-09-04 10:20 -0700
                Re: Forth CPUs with NO Interrupts Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-02 23:35 +0200
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 18:09 -0400
                Re: Forth CPUs with NO Interrupts Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-03 02:07 +0200
                Re: Forth CPUs with NO Interrupts rickman <gnuarm@gmail.com> - 2015-09-02 20:49 -0400
                Re: Forth CPUs with NO Interrupts Bernd Paysan <bernd.paysan@gmx.de> - 2015-09-03 14:30 +0200
    Re: Forth CPUs with NO Interrupts hughaguilar96@gmail.com - 2015-09-02 14:23 -0700

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