Reading/dumping TSOPs

[spacies]

Who can guide me in doing this.
I have read threads to my eyes bled and now I think I am almost there.

Basically I wanna extract and modify info from a TSOP.

I don't wanna risk damage to the TSOP so I think a proper TSOP clip will a good purchase, even though they are expensive.


Questions:

1: What is the best software for doing this or does it come down to what software is on the TSOP?

2: If I am successful in extracting the codes, how easy is it going to be to change things?

3: If I am too dumb to read/modify the info, who wants to help?

That will do for now.

 

[MonMotha]

I presume you mean a flash device in TSOP (or TSSOP) packaging.  The easiest way (by far) to do this is get a real device programmer with an appropriate socket adapter.  This setup will probably run you about $700-1000 including the adapter.  Software will be included which can both read and reprogram the device.  Most of these programmers can program a wide array of devices, including UV erase EPROMs, flash, serial EEPROMs, microcontrollers, NVSRAMs, PLDs, and more.  These are available with all sorts of PC interfaces ranging from proprietary ISA/PCI card based to serial to parallel port to USB or even sometimes IEEE1394 ("Firewire").

If you don't want to spend that kind of cash, you'll have to hack yourself together something that'll likely use a PC parallel port.  Some designs include a microcontroller that you'll have to program somehow (often with a simple "wires only" parallel port cable).  There are designs out there that you can build or you can design your own if you prefer.  I'm guessing some places sell kits or even pre-made devices of this nature.  These sort of devices are usually restricted to programming only flash based parts (no high-voltage programming capabilities for things like UV erase EPROMs), but most designs will allow reading of about anything.  You'd likely have to either buy or fabricate a board to mount the TSOP/TSSOP socket on, since those are not usually perfboard friendly.

Of course, you'll ahve to get the chip off the board first, and that's not easy.  Some boards will have an interface (such as a JTAG TAP) that will let you read the data off (usually slowly) without removing the chip.  If your board has this, I'd use that.

As far as making sense of the image, it depends on what it's an image of and what you know about it.  If you know absolutely nothing about the application it's coming from and don't know the assembly language for the CPU architecture it's on, things can be a bit challenging, to say the least.

[spacies]

Thanks,

Yip, its a flash device.
I don't want to even try to remove it to risk damage.

I have seen hacks where theymake a 'clip' and use a smartcard reader.
Although it seems to work, I would prefer a proper device.


There is a CPLD on the board as well.

And yes, there is a JTAG.

Keep talking.

[MonMotha]

Well, if it's a NAND type flash device, you might be able to use a SM or XD reader to read it, but that's doubtful since most of those don't allow raw access to the flash, but rather enforce a specific FTL.

I'd say grab a JTAG dongle and enumerate out the JTAG chain.  The CPU and CPLD are both likely to be on it, as well as possibly some other stuff.  Using JTAG is usually the easiest way if you want to read the chip while it's on the board.  Using an external device to read the flash requires forcing the other devices off the bus anyway, and the easiest way to do that is often JTAG. 

If you can find the docs on the processor, you can probably put it in reset, and then use EXTEST instructions to read out the contents of the flash manually.  Writing is also possible.  This is how the program called "jflash" works on StrongARM devices, though it was intended for NOR flash.  There should be plenty of examples of this.  What board is this that you're working with?  Do you have any specs such as a manual for the CPU?

Be aware that NAND chips are kinda finicky.  They are allowed to ship from the factory with bad blocks, and are also often allowed to randomly develop bad blocks over time with virtually no requirements on minimum erase cycles.  You may have to understand a fair bit about the flash filesystem so that you can work around any bad blocks which arise if you want to place modified data back on the flash.

[Angry_Radish]

Wow, I just had to pop in and say it took me probably a full 30 seconds to realize I wasn't on one of my dishnet forums, great info though!