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 18:11 -0400
Organization	A noiseless patient Spider
Message-ID	<ms7s40$5fk$2@dont-email.me> (permalink)
References	(8 earlier) <ms6p0k$f5v$1@dont-email.me> <ms78mf$hp1$1@dont-email.me> <2b10f494-9649-4a0a-8520-5d4a1187ac16@googlegroups.com> <ms7nos$hpi$1@dont-email.me> <557e316e-d1eb-4dc9-bc34-243ddd7c1730@googlegroups.com>

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On 9/2/2015 5:55 PM, Mux wrote:
>> I am speculating, but if you are using the Xilinx SRL (if that is the
>> right name), thy are implemented as the LUT latches with counters to
>> work as a shift register.  They don't have full data paths to shift data
>> between the latches and using counters saves power too.  If you are
>> implementing a proper shift register using FPGA registers, you are using
>> a 2 to 1 mux on every bit of every register to get bi-directionality.
>>
>
> Yeah, but since they're wedged inbetween latches / registers (for lack of a better word), the performance you get is higher. For a register file you need an NxM multiplexer which usually comes out slower. Add to that the fact that you now have need a bi-directional counter to address into that and your critical path has become even slower.

And you only get them on Xilinx parts.  Xilinx <> FPGA

I don't optimize until I know I have an issue that requires 
optimization.  Maybe the optimization is minimizing LUT usage?


>> BTW, blockrams are far from "free".  They are just a different color of
>> money.
>
> Oh, I'm sure :-)
>
> -Y
>


-- 

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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