Re: AREF bypass capacitance on ATMega2560?

From	rickman <gnuarm@gmail.com>
Newsgroups	sci.electronics.design, comp.arch.embedded
Subject	Re: AREF bypass capacitance on ATMega2560?
Date	2013-09-07 10:00 -0400
Organization	A noiseless patient Spider
Message-ID	<l0fbin$v4p$1@dont-email.me> (permalink)
References	(4 earlier) <b7n1d9F4bj0U1@mid.individual.net> <l0ddpd$14k$1@dont-email.me> <b8ushnFif3nU1@mid.individual.net> <l0dggl$i7r$1@dont-email.me> <87y579yr74.fsf@devereux.me.uk>

Cross-posted to 2 groups.

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On 9/7/2013 4:24 AM, John Devereux wrote:
> rickman<gnuarm@gmail.com>  writes:
>
>> If your FPGA designs are expensive or power hungry, then you are doing
>> things you can't do in an MCU or you are not using FPGAs properly.
>> They don't need to use any more power than an MCU and in many cases
>> less. They certainly don't need to be significantly more expensive
>> unless you consider every dollar in your designs.  At the very low end
>> MCUs can be under $1 and still have reasonable performance.  For $1
>> you can't get much in the way of programmable logic.  For $3 however,
>> you can get a chip large enough for a CPU (with math) and room for
>> your special logic.
>
> I've never used an FPGA, microcontrollers have increased in speed faster
> than my needs so far. So I can usually bitbang everything or use a
> peripheral. I used PLDs for glue logic back in the day but that's it. Oh
> and I bought a small xilinx dev kit which I got to make a led flash then
> put in a drawer for 15 years.

So your use of MCUs is based on inertia?

> But could you give an example of your $3 one? Or a favorite?

A startup company called Silicon Blue came out with a line of FPGAs 
targeted to the high volume, low power market that exists for portable 
devices.  They were preparing their second device family and were bought 
by Lattice Semi.  The first family was dropped and the second family is 
the iCE40 (for 40 nm).  They are very low power although smallish.  The 
largest one has 8 kLUTs, the smallest 384 LUTs.

Last winter I was looking at designing a very low power radio controlled 
clock to run in one of these.  They were still playing a shell game with 
the devices in the lineup and the 640 LUT part I wanted to use was 
dropped... :(  The only real problem I have with these devices is the 
packaging.  Because of the target market the packages are mostly fine 
pitch BGAs.  Great if you are making a cell phone, not so great if you 
are designing other equipment.

You can get the 1 kLUT parts for under $3 and possibly the 4 kLUT parts. 
  It has been a while since I got a quote.  The 1 kLUT part is big 
enough for a soft core MCU plus some custom logic.

BTW, with MCUs Digikey will give you a realistic price quote.  In the 
FPGA world the distis never give you a good price unless you ask for a 
quantity quote.  I have gotten prices quoted to me that were half the 
list price.  FPGA companies play a different marketing game and have a 
lot of room to negotiate in order to buy a socket.

-- 

Rick

Thread

AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-08-19 13:14 -0700
  Re: AREF bypass capacitance on ATMega2560? John Devereux <john@devereux.me.uk> - 2013-08-20 20:16 +0100
  Re: AREF bypass capacitance on ATMega2560? Vladimir Vassilevsky <nospam@nowhere.com> - 2013-08-21 14:47 -0500
    Re: AREF bypass capacitance on ATMega2560? Jim Stewart <jstewart@jkmicro.com> - 2013-08-21 13:18 -0700
    Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-08-21 16:38 -0700
      Re: AREF bypass capacitance on ATMega2560? "Tim Williams" <tmoranwms@charter.net> - 2013-08-21 21:30 -0500
        Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-08-22 10:51 -0700
          Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-06 16:26 -0400
            Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-06 13:33 -0700
              Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-06 17:12 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-06 16:10 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-06 23:59 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 08:10 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 13:03 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 10:59 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 14:54 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 12:39 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 16:44 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 14:48 -0700
                Re: AREF bypass capacitance on ATMega2560? "Tim Williams" <tmoranwms@charter.net> - 2013-09-07 17:10 -0500
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 15:34 -0700
                Re: AREF bypass capacitance on ATMega2560? Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2013-09-08 00:57 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 16:56 -0700
                Re: AREF bypass capacitance on ATMega2560? Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2013-09-09 17:07 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-09 10:19 -0700
                Re: AREF bypass capacitance on ATMega2560? Paul <paul@pcserviceselectronics.co.uk> - 2013-09-09 20:27 +0100
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-09 12:55 -0700
                Re: AREF bypass capacitance on ATMega2560? Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2013-09-11 09:44 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-11 07:27 -0700
                Re: AREF bypass capacitance on ATMega2560? Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2013-09-13 12:42 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-14 11:56 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 19:38 -0400
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-07 17:39 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 23:20 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 07:41 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-07 11:17 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 13:23 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:19 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-08 14:03 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 19:42 -0400
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-08 17:18 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-09 13:13 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 20:21 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-10 23:42 -0400
                Re: AREF bypass capacitance on ATMega2560? John Devereux <john@devereux.me.uk> - 2013-09-07 09:24 +0100
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 10:00 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-07 11:32 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 13:35 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:30 -0400
                Re: AREF bypass capacitance on ATMega2560? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2013-09-09 09:56 -0400
                Re: AREF bypass capacitance on ATMega2560? Robert Wessel <robertwessel2@yahoo.com> - 2013-09-12 11:50 -0500
                Re: AREF bypass capacitance on ATMega2560? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2013-09-12 15:06 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-12 14:57 +0200
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-13 00:21 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-13 14:08 +0200
                Re: AREF bypass capacitance on ATMega2560? Tom Gardner <spamjunk@blueyonder.co.uk> - 2013-09-13 15:15 +0100
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-13 11:46 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-13 18:43 +0200
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-13 19:14 +0200
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-13 15:26 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-13 15:24 -0400
                Re: AREF bypass capacitance on ATMega2560? David Brown <david.brown@removethis.hesbynett.no> - 2013-09-13 20:22 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 09:32 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 13:44 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 12:46 -0700
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-07 13:33 -0700
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 13:46 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 17:05 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 15:23 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 19:02 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 16:45 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 23:16 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 08:05 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-08 14:27 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 12:56 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 23:07 -0400
                Re: AREF bypass capacitance on ATMega2560? Tom Gardner <spamjunk@blueyonder.co.uk> - 2013-09-11 10:05 +0100
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-11 07:49 -0700
                Re: AREF bypass capacitance on ATMega2560? Paul <paul@pcserviceselectronics.co.uk> - 2013-09-11 16:54 +0100
                Re: AREF bypass capacitance on ATMega2560? "Tim Williams" <tmoranwms@charter.net> - 2013-09-11 11:25 -0500
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-11 09:49 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:40 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:38 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 09:34 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-08 14:29 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 13:01 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 16:22 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 23:09 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 16:15 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 14:20 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 18:15 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 15:57 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 19:46 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-08 17:15 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 20:20 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-09 07:17 -0700
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-09 12:17 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-09 19:30 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-09 16:38 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-10 14:02 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 23:41 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-11 00:04 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-11 07:53 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-11 21:50 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 09:58 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-12 18:54 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-12 16:17 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 10:03 -0700
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-12 19:24 +0200
                Re: AREF bypass capacitance on ATMega2560? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2013-09-12 20:38 +0300
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 11:23 -0700
                Re: AREF bypass capacitance on ATMega2560? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2013-09-12 22:36 +0300
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 12:41 -0700
                Re: AREF bypass capacitance on ATMega2560? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2013-09-12 23:08 +0300
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 11:19 -0700
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-12 18:59 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-13 13:00 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-14 12:05 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-12 16:03 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-12 14:42 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-13 00:24 -0400
                Re: AREF bypass capacitance on ATMega2560? Piotr Wyderski <peter.pan@neverland.mil> - 2013-09-13 14:27 +0200
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-14 12:07 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-15 02:26 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-15 09:51 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-13 20:06 -0400
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 16:50 -0400
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-07 14:33 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 19:07 -0400
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-07 16:31 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 23:38 -0400
                Re: AREF bypass capacitance on ATMega2560? Paul Rubin <no.email@nospam.invalid> - 2013-09-08 20:19 -0700
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 23:36 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:46 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 11:36 -0400
                Re: AREF bypass capacitance on ATMega2560? John Devereux <john@devereux.me.uk> - 2013-09-08 09:04 +0100
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-08 13:42 -0400
                Re: AREF bypass capacitance on ATMega2560? John Devereux <john@devereux.me.uk> - 2013-09-08 19:04 +0100
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-08 07:29 -0400
                Re: AREF bypass capacitance on ATMega2560? John Devereux <john@devereux.me.uk> - 2013-09-09 08:56 +0100
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-10 23:54 -0400
                Re: AREF bypass capacitance on ATMega2560? krw@attt.bizz - 2013-09-08 16:24 -0400
                Re: AREF bypass capacitance on ATMega2560? Ulf Samuelsson <ulf_samuelsson@invalid.telia.com> - 2013-09-07 20:11 +0200
                Re: AREF bypass capacitance on ATMega2560? rickman <gnuarm@gmail.com> - 2013-09-07 15:06 -0400
                Re: AREF bypass capacitance on ATMega2560? Joerg <invalid@invalid.invalid> - 2013-09-07 12:54 -0700
    Re: AREF bypass capacitance on ATMega2560? Ulf Samuelsson <ulf_samuelsson@invalid.telia.com> - 2013-09-02 22:27 +0200

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