Info on 28F512 FLASH ROM !!

[zimbali]

Hi,
I have been looking several days on the net to find some datasheet or technical notes or whatever about 28F512 Flash roms. But it seems there is nothing on the net. If someone has any datasheet or something I would appretiate it too much.

Thanks in advance for any help.

Regards

If you share what you know, you'll never forget it.

Cheers
Zimbali

 

[IRstuff]

I don't understand why you're having some much difficulty. I ran a search on Google and the first hit yielded:

http://www.fe.up.pt/~victorm/DataSheet/Diversos/AM28F512.pdf

TTFN

 

[designchain]

Not only that - there are HUNDREDS OF HITS at partminer - READ THE FAQ: faq797-685

--
Mike Kirschner
Design Chain Associates, LLC

http://www.designchainassociates.com

 

[zimbali]

Hi,
Thanks for your replies. The site was realy good. I didn't find exactly what I was looking for, in the Datasheet as I expected before. I'd like to find a trick to read the memory if it is locked to be read. I'm not quite sure if puuling up RESET pin to +12V will let me to read the content or not. Any idea?

cheers



If you share what you know, you'll never forget it.

Cheers
Zimbali

 

[melone]

I have never heard of locking memory from READING....

 

[zimbali]

Yep melone,

You're right. I was under the impression of Microcontrollers and thought it's the same for memories as they have all (or part of) the program in them. Once, I tried to extract the codes of a tiny 80C2051 but it was locked from reading. It was used in a car Dashboard to control the tachometer. I had to write the software myself. Afterwards I found some methods to attack the microcontrollers (and the easiest ones are 8051 ones!) to burn the hardware protection inside them and read the content. I don't like calling it "Hacking" as it is Reverse Engineering to me and the project starts right there not finishes!!!

Basically, there was a mode in 29F200 (Next generation of the one I asked) that has a Write and Erase Protection, which is not permanent though and completly programable. It was this, that gave me this impression when I was glancing the datasheet.

So, if somebody wants to steal the program (or at least a part of it) they can do that, easily put them in some eprom programmer/ readre like EMP-20 or something and read it..., seems easy and true but still not logical to me, because:

28F256, 28F512, 29F200 and 28F400 are the most popular ROMs in Car ECUs. All maps and tables and obviuosly codes are located inside these ROMs. I was really thinking that there should be a protection for all those data as they are expensive to build up for a factory.

Anyway thanks for all hints. I'm gonna open an ECU and see if I can read the data.

Regards

If you share what you know, you'll never forget it.

Cheers
Zimbali

 

[melone]

What you are talking about is sounds like 2 seperate scenarios:

1) Reading on-board memory from a 8051
2) Reading memory from a standalone Flash device

Scenario 1, can be tricky if you don't want to power up the 8051, but scenario 2 is trivial.

Having used the type of flash that you are using, I must admit that I have never heard of READ protection! The only thing that comes close is when you attempt to to burst type access (since a specific algorithm must be performed to set everything up).

There is a very easy way to prevent someone from removing a flash device and reading out the memory / program directly via a off-the-shelf programmer.....just swamp a couple of address and data lines going between the flash and the micro. Perhaps, this is what you are encountering?

 

[melone]

typo....swamp should be swap

 

[zimbali]

Thanks melone,

Actually I was thinking of the same strategy to be used to protect the program. I was thinking of a whole block to be used in the Micro itself, but your idea seems more effective.

As far as I know, All tables (which are the ones that I need, luckily) are in that Flash ROM (stand-alone one), because the maps and tables are kind of adaptive maps. The base table is designed for one (or some limited) prototype engine(s). But each engine is slightly different from the others and this asks for a bit different settings. The required changes will be done by the Micro itself during the first days of engine life! by observing the engine behaviour and this updating asks for a flash device.

Cheers


If you share what you know, you'll never forget it.

Cheers
Zimbali

 

[nbucska]

Read protecting a stand-alone RAM would convert it to a
WROM (Write Only Memory )

<nbucska@pcperipherals.com>

 

[zimbali]

Very wise idea , thanks anyway!

If you share what you know, you'll never forget it.

Cheers
Zimbali

 

[designchain]

I recall getting a joke datasheet in the early '80s for a Write-Only Memory when I worked at Intel. I grabbed an empty (no die) 28 pin cerdip package with a quartz window and, voila! A sample! B-)

Mike

--
Mike Kirschner
Design Chain Associates, LLC

http://www.designchainassociates.com