Lock only flash programming

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axos88
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Joined: Mon. Jan 22, 2007
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Posted by axos88: Sun. Nov 22, 2009 - 06:15 PM
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Hello!

Is there a way to disable only programming the flash, but leave the eeprom "changeable"?

Currently I am using a Mega8, but if there is an other device that can do this, I can change it, haven't made the prototype yet.

I am storing settings in the EEPROM, and would like a computer to be able to update them. The simplest approach would be to give them a serial programmer, and the PC would just update the EEPROM contents, using avrdude, and reset the device, but I want to lock the flash memory down so they can't clone it.

Regards,

axos88

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AVR Microcontrollers, megaAVR and tinyAVR
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Bronze Markjs
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Joined: Wed. Mar 28, 2001
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Location: Sydney, Australia (Gum trees, Koalas and Kangaroos, No Edelweis, but plenty of Corona beer)
Posted by js: Sun. Nov 22, 2009 - 08:43 PM
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I don't think the EEPROM can be locked by the fuse bits. However "I want to lock the flash memory down so they can't clone it." only applies if the whole thing is not making much money, if it's worth a lot of money then do a search and you will find many threads that shows that a locked chip is as good as a locked house or a locked safe. (ie they CAN be broken in by determined people)

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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