Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.arch.embedded > #28195

Re: $0.03 microcontroller

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.arch.embedded
Subject Re: $0.03 microcontroller
Date 2018-10-13 12:46 +0200
Organization A noiseless patient Spider
Message-ID <ppsido$59m$1@dont-email.me> (permalink)
References (1 earlier) <874ldtp66e.fsf@nightsong.com> <tl1urdtvs2rr7pqkab7o0rgdk7kecok7fs@4ax.com> <87in28nktr.fsf@nightsong.com> <pppg8a$q0u$1@solani.org> <db074a68-df45-4b56-8ae4-80ebc451eaeb@googlegroups.com>

Show all headers | View raw

On 12/10/18 18:11, gnuarm.deletethisbit@gmail.com wrote:
> On Friday, October 12, 2018 at 2:50:53 AM UTC-4, Philipp Klaus Krause wrote:
>> Am 12.10.2018 um 01:08 schrieb Paul Rubin:
>>> upsidedown@downunder.com writes:
>>>> There is a lot of operations that will update memory locations, so why
>>>> would you need a lot of CPU registers.
>>>
>>> Being able to (say) add register to register saves traffic through the
>>> accumulator and therefore instructions.
>>>
>>>> 1 KiB = 0.5 KiW is quite a lot, it is about 10-15 pages of commented
>>>> assembly program listing.
>>>
>>> It would be nice to have a C compiler, and registers help with that.
>>>
>>
>> Looking at the instruction set, it should be possible to make a backend
>> for this in SDCC; the architecture looks more C-friendly than the
>> existing pic14 and pic16 backends. But it surely isn't as nice as stm8
>> or z80.
>> reentrant functions will be inefficent: No registers, and no sp-relative
>> adressing mode. On would want to reserve a few memory locations as
>> pseudo-registers to help with that, but that only goes so far.
> 
> CPUs like this (and others that aren't like this) should be
> programmed  in Forth. It's a great tool for small MCUs and many times can be hosted
> on the target although not likely in this case. Still, you can bring
> enough functionality onto the MCU to allow direct downloads and many
> debugging features without an ICE.
> 
> Rick C.
> 

Forth is a good language for very small devices, but there are details 
that can make a huge difference in how efficient it is.  To make Forth 
work well on a small chip you need a Forth-specific instruction set to 
target the stack processing.  For example, adding two numbers in this 
chip is two instructions - load accumulator from memory X, add 
accumulator to memory Y.  In a Forth cpu, you'd have a single 
instruction that does "pop two numbers, add them, push the result". 
That gives a very efficient and compact instruction set.  But it is hard 
to get the same results from a chip that doesn't have this kind of 
stack-based instruction set.

Back to comp.arch.embedded | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

$0.03 microcontroller Clifford Heath <no.spam@please.net> - 2018-10-10 12:05 +1100
  Re: $0.03 microcontroller lasselangwadtchristensen@gmail.com - 2018-10-10 16:12 -0700
  Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-10 17:51 -0700
    Re: $0.03 microcontroller lasselangwadtchristensen@gmail.com - 2018-10-10 18:56 -0700
  Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-10 19:29 -0700
    Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-11 11:39 +0300
      Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-11 16:08 -0700
        Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-12 08:50 +0200
          Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-12 09:44 +0200
            Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-12 21:30 +0300
              Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-12 22:06 +0200
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-12 23:45 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-13 21:47 +0200
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-14 11:58 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-15 08:14 +0200
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-11 09:27 +0100
                Re: $0.03 microcontroller Klaus Kragelund <klauskvik@hotmail.com> - 2018-12-26 02:23 -0800
              Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-15 10:44 +0200
                Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-15 07:29 -0700
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-16 09:19 +0200
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-16 13:48 +0200
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-15 21:34 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-16 09:29 +0200
                Re: $0.03 microcontroller Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2018-10-15 21:22 +0200
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-16 10:00 +0200
                Re: $0.03 microcontroller Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2018-10-16 22:52 +0200
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-16 14:01 -0700
                Re: $0.03 microcontroller Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2018-10-17 00:03 +0200
                Re: $0.03 microcontroller Clifford Heath <no.spam@please.net> - 2018-10-17 09:22 +1100
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-16 15:29 -0700
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-17 00:46 +0200
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-17 09:35 +0300
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-17 09:31 +0200
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-17 07:08 -0700
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-17 18:37 +0300
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-17 10:04 -0700
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-17 23:07 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-17 08:23 +0200
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-17 19:43 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-17 20:24 +0200
                Re: $0.03 microcontroller George Neuner <gneuner2@comcast.net> - 2018-10-17 11:31 -0400
            Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-05 12:41 +0100
          Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-12 09:11 -0700
            Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-13 12:46 +0200
              Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-13 05:06 -0700
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-13 18:00 +0300
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-13 18:27 +0200
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-13 20:50 +0300
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-14 14:26 +0200
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-13 18:20 -0700
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-14 08:53 +0200
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-14 08:55 +0200
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-14 14:32 +0200
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-13 18:21 +0200
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-13 18:32 -0700
                Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-13 19:02 -0700
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-14 14:37 +0200
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-14 14:59 +0200
                Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-13 11:06 -0700
            Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-13 18:31 +0300
              Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-13 19:46 +0300
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-13 19:59 +0300
                Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-13 21:31 +0300
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-13 22:19 +0300
                Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-13 21:24 +0200
                Re: $0.03 microcontroller Niklas Holsti <niklas.holsti@tidorum.invalid> - 2018-10-13 22:50 +0300
                Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-14 14:39 +0200
                Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-15 05:11 -0700
              Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-13 21:03 +0300
              Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-13 18:25 -0700
          Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-15 14:20 +0200
    Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-21 16:27 +0300
      Re: $0.03 microcontroller jim.brakefield@ieee.org - 2018-10-21 07:47 -0700
        Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-21 08:08 -0700
          Re: $0.03 microcontroller jim.brakefield@ieee.org - 2018-10-21 09:31 -0700
            Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-21 10:51 -0700
              Re: $0.03 microcontroller jim.brakefield@ieee.org - 2018-10-21 12:44 -0700
                Re: $0.03 microcontroller Brett <ggtgp@yahoo.com> - 2018-10-22 00:28 +0000
          Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-21 21:43 +0200
      Re: $0.03 microcontroller Phil Martel <pomartel@comcast.net> - 2018-10-21 11:03 -0400
      Re: $0.03 microcontroller George Neuner <gneuner2@comcast.net> - 2018-10-21 20:59 -0400
  Re: $0.03 microcontroller Michael Kellett <mk@mkesc.co.uk> - 2018-10-11 14:04 +0100
    Re: $0.03 microcontroller David Brown <david.brown@hesbynett.no> - 2018-10-11 15:56 +0200
      Re: $0.03 microcontroller Michael Kellett <mk@mkesc.co.uk> - 2018-10-13 09:35 +0100
        Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-13 13:06 -0700
          Re: $0.03 microcontroller Michael Kellett <mk@mkesc.co.uk> - 2018-10-14 11:30 +0100
  Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-12 10:18 +0200
    Re: $0.03 microcontroller upsidedown@downunder.com - 2018-10-12 21:39 +0300
      Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-08 13:53 +0100
        Re: $0.03 microcontroller Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2018-11-08 15:08 +0200
          Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-08 14:34 +0100
        Re: $0.03 microcontroller upsidedown@downunder.com - 2018-11-08 21:52 +0200
          Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-08 21:56 +0100
            Re: $0.03 microcontroller upsidedown@downunder.com - 2018-11-09 00:35 +0200
              Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-11-09 09:00 +0100
    Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-15 14:19 +0200
  Re: $0.03 microcontroller Tim <cpldcpu+usenet@gmail.com> - 2018-10-14 01:46 +0200
    Re: $0.03 microcontroller Theo <theom+news@chiark.greenend.org.uk> - 2018-10-14 10:55 +0100
      Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-24 15:57 +0200
  Re: $0.03 microcontroller Philipp Klaus Krause <pkk@spth.de> - 2018-10-15 14:35 +0200
    Re: $0.03 microcontroller raimond.dragomir@gmail.com - 2018-10-15 06:05 -0700
      Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-15 07:19 -0700
        Re: $0.03 microcontroller Paul Rubin <no.email@nospam.invalid> - 2018-10-15 07:26 -0700
          Re: $0.03 microcontroller gnuarm.deletethisbit@gmail.com - 2018-10-15 07:30 -0700

csiph-web