On Sat, 14 Jun 2008 08:36:57 -0700, Joerg
<n...@removethispacbell.net> wrote:

>Jonathan Kirwan wrote:
>> On Fri, 13 Jun 2008 16:23:42 -0700, Joerg
>> <n...@removethispacbell.net> wrote:
>> 
>>> Jonathan Kirwan wrote:
>>>> On Fri, 13 Jun 2008 15:42:27 -0700, Joerg
>>>> <n...@removethispacbell.net> wrote:
>>>>
>>>>> Hello All,
>>>>>
>>>>> After some problems a client saw I was treated to my own dose of what is 
>>>>> likely flash loss: The uC in our mailbox door has become erratic. I 
>>>>> installed it about three months ago and half of the day it receives a 
>>>>> good pelting from the sun. First it began not recognizing some keys, 
>>>>> then it started doing weird stuff like lock cycling. Things it wasn't 
>>>>> meant to ever do. Batteries, contacts and such look ok, reset didn't 
>>>>> help, so that's not it.
>>>>>
>>>>> TI has an app note about the topic:
>>>>> http://focus.ti.com/lit/an/slaa392/slaa392.pdf
>>>>>
>>>>> Figure 1 looks scary above the 80C range. Later they presented another 
>>>>> test with a different bake cycle which makes things look better but who 
>>>>> knows.
>>>>>
>>>>> What is you experience with respect to flash errors on uC that are 
>>>>> exposed to elevated temperatures as most outdoors applications are?
>>>> I only have some small experience here with the MSP430.  It seems to
>>>> operate at 140C at 3V and 3.3V for the several-hour long tests I've
>>>> done.  But some bad experiences in storing data into the flash at that
>>>> temp and even at 3.3V and higher.  But I didn't need the darn thing to
>>>> survive all that long, either.
>>> Wow, problems within hours at 140C? Not cool :-(
>> 
>> No.  No problems, at all.  Just that I didn't run them for more than
>> about 5 hours at a time.  Same one ran for weeks, though, at periodic
>> elevated temperatures.  I was just collecting data from a rotating hot
>> surface and wanted to just stick the whole contraption there while it
>> stored a few bits of data into RAM.  The battery was the problem.
>
>However, you said "But some bad experiences in storing data into the 
>flash at that temp and even at 3.3V and higher."

Yes, I did.  I gather you want to do that.

>>>> I haven't read, for understanding, the data sheet you mentioned.  I
>>>> just downloaded it, though, and thanks for pointing it up.  I think it
>>>> wasn't around when I looked a few years back and I'm glad that you
>>>> pointed it up for me.
>>>>
>>>> Your obvious solution is to move north about a thousand miles.  ;)
>>> My wife would absolutely not do that.
>> 
>> Oregon is absolutely beautiful!  I've got pileated woodpeckers, 4
>> kinds of squirrels including a flying squirrel (nocturnal), peafowl,
>> chickens, guinea hens, turkeys and so on -- tall 60-80 year old firs,
>> two kinds of ferns, rhododendrons that bloom in succession around the
>> place, and it looks like a lush rain-forest national forest when you
>> walk the paths on the property.  Lots of acres, 5000 sq ft home, 1/4
>> mile driveway to the house, view of the mountains, 5 minutes to a
>> hospital and 20 minutes to the PDX international airport, a 17 mile
>> well-maintained walking and horse trail that goes from 1/2 mile away
>> from my home to the Willamette River in Portland, and it cost me $330k
>> in 2002.  Prices are still low, too.  Next door has been on the block
>> for 2 years, is a million dollar home (tax appraisal price) with about
>> 4500 sq ft and 5 acres, and is being offered at $599k now.  I'm told
>> they'd accept under $500k.  Neighbors are wonderful, too.
>
>That sure sounds mouth-watering. But my wife likes places where there is 
>no winter (and now ours get colder every year ...) and I'd have a wee 
>problem with the property tax rates up there. 2% or more is IMHO 
>confiscatory. Oh, and I like proposition 13 (prop tax increase cap) in 
>California because I do not trust politicians enough to toss them the 
>keys to my bank account.

My place is appraised at $850k (down there, I know that is just a
shack but up here it's 5000 sq ft of quality, showy home and lots of
acres of prime hilltop land) and my property taxes are $4400/year.
Which is kind of high, I admit.  It's the income taxes you'll probably
hate.  It's a graduated rate, but I think the top rate (which applies
to most engineers, without even asking) is 9%.  However, no sales tax.

>> 3' of fantastic soils, 45" of rain a year nice and evenly distributed
>> all year 'round in a constant drizzle, and everything grows where you
>> throw the seed, no digging needed.  What could be better?  ;)
>
>Ah, you shouldn't have written "drizzle", my wife would hate that kind 
>of weather.

I did that on purpose.  I didn't want to make it seem too inviting.
Actually, I've come to appreciate the constant press of low clouds
overhead and the slippery feel of moist moss as you carefully walk
across your one year old, rotting wooden deck.

Jon

Joerg wrote:

> Jim Granville wrote:
> 
>> For more critical uses, Infineon seem to have well-spec'd uC -
>> their new ones all have Error Correcting Flash, and 125'C models.
>>
>> http://www.infineon.com/XC800
>>
>> Also recently added are a series of Transmitter ICs for Wireless 
>> Control, that have Sub 1GHz Transmitters, and Low power Flash C51's
>> - one targets Tire Pressure, at Automotive temp range.
>> http://www.infineon.com/cms/en/product/promopages/pma5110/index.html
>>

and they also have a 140'C rated variant....


> Aha! Thanks. Seems there is some hope. Although I am not much of an 
> Infineon fan. The reaction time of their CA office can be, well, just 
> like the name suggests, infinity.

They do seem to be expanding use of Digikey.

Digikey shows 4,153 Infineon items, of which 275 are Microcontrollers,
and of those 46 are XC8xx series.

[Just not yet the nice looking 20 pin XC864, or 64K XC878's, or
the Wireless Control ones above ..... too new...  - sigh...]

-jg

On Sat, 14 Jun 2008 09:40:25 +0200, Frank Buss <f...@frank-buss.de>
wrote:

>Jonathan Kirwan wrote:
>
>[...]
>> 3' of fantastic soils, 45" of rain a year nice and evenly distributed
>> all year 'round in a constant drizzle, and everything grows where you
>> throw the seed, no digging needed.  What could be better?  ;)
>
>Sounds great if you want to become a farmer :-)

Our family grows/raises most of the food we consume.  It's nice
knowing where it all comes from and how it was treated and prepared.

>I'm living near Cologne
>centre, but a quiet back road near the Rhein. Just a rented flat and not
>acres of grass and bushes around it, but supermarkets, stores, pubs,
>restaurants, theaters, cinemas, parks etc., all within walking distance.

I don't have all that within walking distance.  It's a 5 minute drive
to the nearest hospital, for example, and 20 minutes drive to an
international airport (PDX.)  But we do have a grocery store (not a
supermarket), a pub, a restaurant or two, and many, many parks all
within easy walking distance of home.

Okay.  I'm having fun.  I hope you don't mind if I post a few links to
pictures.

These pictures are from my own land, showing paths that proceed from
my home into the wooded parts of my property:

 http://www.infinitefactors.org/misc/images/Home%20Trails.jpg
 http://www.infinitefactors.org/misc/images/Home%20Trails%202.jpg

That will give you a flavor for the flora.

Mt. Hood rises up from sea level to about 11,300' and is about 15
miles from my home.  Here is how it looks from a lake that is very
close to my home (in the summer):

 http://www.infinitefactors.org/misc/images/Mt%20Hood.jpg

This water fall (among literally more than a hundred within a short
distance) is about a 15 minute drive from home..  over 600 feet:

 http://www.infinitefactors.org/misc/images/Multnomah%20Falls.jpg

The Columbia River flows by Mt. Hood's northern base.  This viewpoint
is actually closer to my home than the above falls -- about a 10
minute drive:

 http://www.infinitefactors.org/misc/images/Crown%20Pt.jpg

All of the above is in relatively easy bicycling distance.

In Oregon, it is illegal to own or fence or otherwise control coastal
land.  Some 400 miles of coastline is public land.  The only state of
the USA that does this, I think.  In any case, here is one photo of
what our coast partly looks like:

 http://www.infinitefactors.org/misc/images/Boardman.jpg

Jon

TheM wrote:

> "Joerg" <n...@removethispacbell.net> wrote in message
news:i0S4k.1439$L...@nlpi065.nbdc.sbc.com...
> 
>>Yeah but that would not be cool. 100W at 6ft isn't that much. Many applications must live in plastic boxes and
there is always a 
>>chance someone with a 5W contractor radio stands right next to them. Or someone fires up a cell phone and the
GSM ones can be 
>>particularly nasty here.
> 
> 
> It could be a design with long supply wires (as antennas) and poor RF
> blocking caps close to uCPU.
> 
> Flash corruption due to EM field at 6 feet distance sounds a bit far fetched.

It will not be a Direct Flash Cell effect, but more likely a Software
crash, that jumps into a Flash Write routine.

This is one reason why many Automotive designs insist on a FLASH_ENABLE 
pin, so that a simple SW crash CANNOT cause un-recoverable damage.

We have some designs that will NOT use IAP Flash controllers, for 
exactly the same reason.

Adding IAP is a convenient feature, but it also can be a point of weakness.

-jg

Robert Adsett wrote:

> In article <pCV4k.14650$H...@news.siol.net>, TheM says...
> 
> First the Ramtron devices are FeRam not MRAM.
> 
> Second Ramtron has also been claiming unlimited writes for some time 
> now.  IIRC the limit was a function of axygen contamination.  Apparently 
> they solved that problem.

Not quite:
The latest Mar 2008 data for the FM25H20 2MBit FRAM, (40MHz) specs 10^14 
Wd/Wr,
(which I guess is per Byte?).

Most data application will be well under that, but it could start to
bother an execute-from-flash design, sitting in a tight loop.

These parts have very Niche-prices, around 20x that of vanilla flash,
so you really have to need their better features :)

-jg

Joerg wrote:
> The flag is the problem. Unfortunately uC manufacturers have not put 
> that much thought into the reset routine. It just jumps to a fixed 
> address and when the data there is corrupt the application is toast.

I'm working with an 89lpc952 (Phillips/NXT) which comes preprogrammed 
with a bootloader in the top Flash sector.  There's a flag that, when 
set, will cause execution to start there instead of the normal reset vector.

You're free to overwrite the bootloader with something else, so perhaps 
that facility could be used for one side of the flipflop?

Of course, the '952 also has IAP which I don't think can be disabled...

-- 
Gordon S. Hlavenka           http://www.crashelectronics.com
          Vote Ron Paul in 2008!  Call 866-737-5066

Frank Buss <f...@frank-buss.de> writes:
> Jonathan Kirwan wrote:
> 
> [...]
> > 3' of fantastic soils, 45" of rain a year nice and evenly distributed
> > all year 'round in a constant drizzle, and everything grows where you
> > throw the seed, no digging needed.  What could be better?  ;)
> 
> Sounds great if you want to become a farmer :-) I'm living near Cologne
> centre, but a quiet back road near the Rhein. Just a rented flat and not
> acres of grass and bushes around it, but supermarkets, stores, pubs,
> restaurants, theaters, cinemas, parks etc., all within walking distance.

And it's well known that (western) Oregonians don't tan,
they rust.

In article <48548fc4$1...@clear.net.nz>, Jim Granville says...
> Robert Adsett wrote:
> 
> > In article <pCV4k.14650$H...@news.siol.net>, TheM says...
> > 
> > First the Ramtron devices are FeRam not MRAM.
> > 
> > Second Ramtron has also been claiming unlimited writes for some time 
> > now.  IIRC the limit was a function of axygen contamination.  Apparently 
> > they solved that problem.
> 
> Not quite:
> The latest Mar 2008 data for the FM25H20 2MBit FRAM, (40MHz) specs 10^14 
> Wd/Wr,
> (which I guess is per Byte?).

Interesting.  Their lower density parts like FM25L512 quote unlimited 
read/write cycles.  Maybe endurance issues have arisen again at finer 
geometries?

> Most data application will be well under that, but it could start to
> bother an execute-from-flash design, sitting in a tight loop.
> 
> These parts have very Niche-prices, around 20x that of vanilla flash,
> so you really have to need their better features :)

For small sizes the price premium over EE is small.  I use them for the 
security of a faster write (the memory is vulnerable for a smaller 
window).

Robert
** Posted from http://www.teranews.com **

On Sat, 14 Jun 2008 15:04:59 -0700, Joerg
<n...@removethispacbell.net> wrote:

>legg wrote:
>> On Fri, 13 Jun 2008 16:31:00 -0700, Joerg
>> <n...@removethispacbell.net> wrote:
>> 
>>> Tim Wescott wrote:
>>  
>>> It's not just this mailbox but also some MSP430 apps at a client. They 
>>> predate my involvement there and we are pretty much stuck with that for 
>>> a while. We are seeing a distinct pattern where those inside smaller 
>>> boxes fail more often than those in larger and more airy enclosures. 
>>> This stuff is used in the south where summers are quite toasty.
>> 
>> I suggest you paint your box or faceplate a different color.
>> 
>> Your aim should be to avoid producing temperatures that are not
>> neccessary in direct sunlight.
>>
>
>Not so easy on an existing product. But from experience it seems the 
>temps weren't all that different between a black box and an off-white 
>one. Maybe the off-white one crept up a little slower.

With all other variables constant, a reduced rate of rise means a
lower end-point of thermal burden. Light colours are preferable where
reflective surfaces are not possible.

Changing the material, or material grade to something that is not
clear/opaque to infrared can also have an effect. A paint overcoat
rather than internal pigment (~of plastic). Adding irregular surface
finish or stippling/ridging may also have a beneficial effect.

Failing that, a sacrificial face-plate on the most exposed surfaces,
decoupled physically from the case itself.

RL

On Sat, 14 Jun 2008 19:48:34 PST,
m...@mojaveg.lsan.mdsg-pacwest.com (Everett M. Greene) wrote:

>Frank Buss <f...@frank-buss.de> writes:
>> Jonathan Kirwan wrote:
>> 
>> [...]
>> > 3' of fantastic soils, 45" of rain a year nice and evenly distributed
>> > all year 'round in a constant drizzle, and everything grows where you
>> > throw the seed, no digging needed.  What could be better?  ;)
>> 
>> Sounds great if you want to become a farmer :-) I'm living near Cologne
>> centre, but a quiet back road near the Rhein. Just a rented flat and not
>> acres of grass and bushes around it, but supermarkets, stores, pubs,
>> restaurants, theaters, cinemas, parks etc., all within walking distance.
>
>And it's well known that (western) Oregonians don't tan,
>they rust.

;)

I just spent a nice day today at a fly-in for nitro and electric
helicopter models.  It was a nice day of about 64-67F and I spent
about 5 hours in the 45-degree N latitude sun.  Horrible sunburn I'm
sitting here suffering from, right now!  (I get 2nd degree burns in 15
minutes in LA, by the way.  I need the cloud cover!)

Jon