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Groups > comp.arch.embedded > #13338
| From | Joerg <invalid@invalid.invalid> |
|---|---|
| Newsgroups | sci.electronics.design, comp.arch.embedded |
| Subject | Re: AREF bypass capacitance on ATMega2560? |
| Date | 2013-09-06 16:10 -0700 |
| Organization | Consultant |
| Message-ID | <b8v5o1Fk9f7U1@mid.individual.net> (permalink) |
| References | (3 earlier) <kv3t3p$mh$1@dont-email.me> <b7n1d9F4bj0U1@mid.individual.net> <l0ddpd$14k$1@dont-email.me> <b8ushnFif3nU1@mid.individual.net> <l0dggl$i7r$1@dont-email.me> |
Cross-posted to 2 groups.
rickman wrote: > On 9/6/2013 4:33 PM, Joerg wrote: >> rickman wrote: >>> On 8/22/2013 1:51 PM, Joerg wrote: >>>> Tim Williams wrote: >>>>> "Joerg"<invalid@invalid.invalid> wrote in message >>>>> news:b7l1blFlu93U2@mid.individual.net... >>>>>>>> I saw people >>>>>>>> using 0.1uF and 0.47uF. The datasheet is silent about stuff like >>>>>>>> that, >>>>>>>> as usual. >>>>>>> It doesn't really matter. >>>>>>> >>>>>> However, not everyone knows that because they don't say much about >>>>>> the >>>>>> innards of the chip. It's my first ATMega case, or maybe the 2nd. >>>>> >>>>> Finally gave up and bit the uC bullet? ;-) >>>>> >>>> >>>> Sometimes you need it. A while ago I even had a switcher design that >>>> would have been totally impossible to do without a uC. But it does >>>> raise >>>> eyebrows if I request timers and port pins and MIPS, probably >>>> because of >>>> my analog background. "YOU want some of the uC resources? What for?" >>> >>> Sounds to me like you need FPGA resources moreso than an MCU. Are you >>> using the ADC or DAC, guess so or are you using the reference for the >>> brownout or something else? DACs are easy in FPGAs, ADCs not as easy. >>> Otherwise FPGAs do everything an MCU does plus... >>> >> >> I nearly always need ADC capability. Not for the brownout, I never trust >> anything on those chips for that, the POR/BOR/WDT goes external. FPGA >> have some downsides, they tend to become large, expensive and sometimes >> power-hungry when you need math capability or an MCU core. > > 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. ... That is often the problem. Sometimes a buck fifty is the pain threshold. Not in this ATMega case, the 2560 is very expensive but comes with lots of ADC and analog muxes and all that. Things that will cost extra with a FPGA solution and eat real estate. For $3 however, you can get a > chip large enough for a CPU (with math) and room for your special logic. > For $3 I can get a big DSP. > >> But the main >> issue for many projects is people. If the client has the experts in >> house like in this case, fine. But if not then one is better off using a >> uC where one can find a programmer in nearly every town. This is one >> reason I am often partial to the 8051. > > Do you work in *every* town? I find if I need a skill, it doesn't > matter where the worker is. ... Not in every town but sometimes way out there. For most work it doesn't matter where the worker is but with uC programming that is often not so. Mainly because things have to be optimized right there at the big machine which for one reason or the other can't be moved into a programmer's bedroom corner in Upper Sendusky. Then it does begin to matter whether or not you have to start flying in people. It's the same with myself. For many assigments I could as well live on East Rarotonga. But not for EMC or noise fixing jobs with larger installations. > ... I also find FPGA design is pretty common > these days. If you are ever short on FPGA design skills, give me a shout. > Could happen. What I often find is people only doing Altera or only Xilinx. With uC it's a bit easier, a PIC guy can be cajoled into programming an AVR, usually. > >> Of course the beauty of FPGA is that the availability of very fast glue >> logic. Most uC are sorely lacking in that domain. > > Yes, the ideal chip would add a section of FPGA fabric to a conventional > MCU and vary the size just as they do the RAM and Flash. I think at > this point the problem is cultural. Most FPGA companies are all about > the big iron selling for $100 a chip min and the MCU makers don't > understand programmable logic. Xilinx and Cypress is good examples. > Zync is a very high end solution, great if it matches your problem. PSOC > is not a bad idea, but their idea of programmable logic isn't worth much. > > Give me a good $10 MCU/FPGA combo and I'll design the world! In the > meantime I'll be using soft cores. They are a lot easier to program > than an MCU anyway. > Things quickly unravel when you start relying on real hardware that is on uC but not on FPGA. Comparators, ADCs, analog muxes, for example. Last week I reviewed a design with some larger FPGA on there. What I found fairly disgusting was how much they had to be babied with the power sequencing. uCs don't have that problem. -- Regards, Joerg http://www.analogconsultants.com/
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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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