Advice Reading firmware ATTiny26

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I purchased a device which I did not create and it has a ATTINY26-16PU.

 

Can someone with experience on ATTINY26-16PU (20 pin DIP) Explain the following:

 

Please answer each of these questions:

 

1. Is it possible to read the firmware of the ATTINY26-16PU of any Device that contains one?

2. Does the chip have any fuses or protection capabilities that would stop me from reading the firmware?

3. Assuming it's possible to read firmware. What programmer would I need?

 

I looked at data sheet and I was unable to find my answers.

 

-Thanks.

 

 

 

 

 

Last Edited: Tue. Dec 10, 2019 - 03:25 AM
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Greetings and welcome to AVR Freaks!

 

Yes, you can read the memory if it is not locked.

 

Yes, it has fuses. See "Memory Programming" section of the manual. Also has Lock Bits which are a kind of fuse. It appears that LBMode = 3 prevents verification (e.g. reading). Note that the fuses, themselves, are locked so you may not even be able to read the fuses if the device is locked.

 

The programming interface appears to be ISP (which uses an SPI hardware bus for access) plus the reset pin.

 

By the way,  Madame Google returns loads of information from the query: How to program Tiny26?

 

As a side note, reading the firmware will tell you very little. It takes a LOT of work to sort it all out. If the programming language was C or C++, then there are a host of operations that are language unique and do not easily reverse-engineer unless you are pretty familiar with the inner workings of C AND the assembly language. The latter can be found in an AVR Assembly Language manual which can be found by  Google.

 

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

Last Edited: Tue. Dec 10, 2019 - 04:21 AM
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1) You can always read something, whether it is the code in the chip or not will depend on the lock bits. Most commercial designs will be locked.

 

2) yes, see (1)

 

3) tiny26 has two mechanisms for flash read/write. One involves special "high voltage" (12V) equipment so is quite complicated. The other is ISP (In System Programming) and you can do that with a $2 USBAsp from ebay.

 

As the chip is only 2K it's unlikely to be doing anything so complex that it would not simply be easier to write code to mimic the functionality from scratch. Trying to decipher extracted code (if not locked) is a thankless task, especially if the code was originally written in C.

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TymerTopCat wrote:
I purchased a device which I did not create and it has a ATTINY26-16PU.

Why do you want to steal someone else's IP?

 

Jiim

 

(Possum Lodge oath) Quando omni flunkus, moritati.

"I thought growing old would take longer"

 

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"It's purely for learning, guv'nor - honest!"

 

frown

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