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Reprogramming a uC FLASH while running code - STM32F

Paul wrote

If your product sells for reasonable money (say $200 or more) the ability to update the firmware in the field is a vital safeguard against a major bug, which would otherwise result in a huge recall, loads of warranty claims, and if you are selling to any big-company customer/reseller or through a big distributor, they will bend you over a barrel and shaft you and make you absolutely pay for the mistake in blood.

That could trash your business totally if you are a small company.

We sell to a US based $20BN company, for example, and they are packed with the usual corporate brown-nosers and political climbers, and the best way to crawl up their internal ladder is to scalp one of the company's suppliers. So we need to be very very careful.

A USB interface is handy for firmware upgrades - even if it is disabled in all normal operating contexts.

If the product has say wifi then it can download the update all by itself (obviously after the customer has consented and performed some enabling actions) and that's even better, because it further reduces the % of returns if you have made some mistake. It could make a difference between the reseller shafting you by returning his entire stock to you (at *your* expense, all the way from say the USA back to Europe) just to make a point, and accepting that the in the field upgrade is a reasonable solution.

I am in a business where our best selling product has 1995 firmware and nobody has yet found a bug, but you can never be sure :)

The ST 32-bit ARM micros are pretty amazing. I have just found they do a little 6mm x 6mm one, with 16k of code space and 4k of RAM, for $1.50. If it wasn't for the higher power consumption, few would bother using the little Atmel or PIC devices. One can span a huge product range with the same device family and crucially the same development tools and same expertise. We still use the AT90S1200 (last time buy was a few years ago but we still have stock) and the last 1 or 2 replacements like the 2313 have already been discontinued (Atmel seem to move on quite quickly these days, sadly, and yes I saw they do ARM processors too) but they are about $1 (10k).

I am looking at the $10 32F with 1MB FLASH.

Reply to
John-Smith
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You can't change anything in your product line? You must not use many semiconductor components (certainly no LSI).

Reply to
krw

You would be amazed how many companies in Aviation and other industries have large stocks of old wafers and packaged devices in nitogen filled packaging and temperature controlled storage.

Changes can be made but the effort to do so is VERY VERY expensive.

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Paul Carpenter          | paul@pcserviceselectronics.co.uk 
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Reply to
Paul

Paul wrote

Actually aviation is my "other" hobby so I know quite a lot about that bit.

I think the main reason they don't change stuff is because there is so little interesting R&D work in that business (they run their cash cows for a decade or more if they can) that anybody with more than 2 braincells leaves pretty quick, and they have no way to fix anything.

:)

Reply to
John-Smith

A decade in aviation is a flash in the pan.

A lot of aircraft take 5-10 years to develop, test, certify....... Then have service lifetime (or product lifetime) of 20-30 years. then some are still flying many decades later, doubt a lot of the newer ones will be.

In one case a device was respun 2 times as ASIC due to process changes before certification, aircraft is in service now, and they have recently bought the last batch of their 'last time buy' to keep them going for 20 years. These are all now in special storage.

The design uses an EEPROM that want EOL something like 12 years ago and they bought a last time buy of wafers for that. I believe they had them packaged before that became a problem. The high temp ceramic packaging is oddball to say the least, and the crystal is in some 64 pin CLCC.

When any new batch of wafers were made for ASIC in question, a tested sample batch was sent to do at least 100 hours aircraft flight time before the wafers could be probed, packaged, tested...

So for one aircraft there is a lot of devices in storage to last 20 years of production.

Aviation, Transport have long life cycles and you dont upgrade unless you have to.

Medical can be longer still, once had call about a medical scanner back in 2002. I asked how old was the scanner, their reply was -

"The earliest record we can find is when it moved to the NEW building in 1968"

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Paul Carpenter          | paul@pcserviceselectronics.co.uk 
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Reply to
Paul

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