Firmware

You need to look up the datasheet of the chip you will be interfacing with.

There are two chips - I posted the numbers.

Alternatively if theres more than one that can be, just use a normal JTAG setup on it and try reading.

lol I now know how people feel when I tell them to try reading. I have actually spent a lot of time looking up jtag and the phone but found nothing. What's a normal jtag setup?

Okay, so I have the BP hooked up. I looked closely and it said 3.0v, so I need the bp to use just 3v, not 3.3. I tried folowing the documentation but minicom gives me command not used in this mode. I would switch modes and try it but I dont want to screw up and brick it.

The more I look into it, the more confused I get. I need to select the tap but I have no documentation on anything.

EDIT: Actually, I may have something. The chip is probably this:
www.dspg.com/products/?itemId=58 ,
The DCX79.
This is getting discouraging.

Never pinned you for the impatient type

lol - I am just worried I bricked this thing. I wasn't sure how to attach the pb to the jtag points so I soldered wires to the jtag points on the phone. The first 10 tries they all fell off as soon as I connected them to the bp. So then I tried leaving the bp to connected the wires while I soldered. So I wound up melting one of the plastic clips. I just hope it wasnt that toxic to breathe in. So I unplugged my soldering iron, let it cool, disconnected the wires, and decided to try again. This time I added some solder to each of the connections. All of them but one stuck. So I tried just fixing that one, but I disconnected another. This happened for the next 10 or so iterations. Finally, All of them stayed on. As I was about to plug it in, I realized that I had soldered over one of the surface mount resistors. So I got the solder off that, but then a wire came loose. So back to step 2. Again finally I got all the pins soldered together, but I had connected two of them. So I desoldered them, they fell out, and back to step 2. It only took me about 4 more tries after that to finally get it, but I burned my hand twice, and I think the board. So I had a fun night.

I also read that it was possible they put a sort of lock on it, that jtag can no longer be used without doing a complete reset of the chip as a sort of firmware protection. Based on my luck recently, it is on this.

I'll read into that sheet. Please post your current setup and any pictures that you can. I will review them on Monday and do a writeup. I don't use my bus pirate for JTAG so its not something I can give you from memory

Okay, Ill post pictures. Thank you for checking for me. I'll keep looking also, but the more research I do the more confused I get. Maybe if I call panasonic they have an technician guide for it

Sorry, finals are coming up.

Here are some pictures:


The wires are connected to the jtag pins, one labled ground, and the one on the bottom labeled 3.0v.

I am pretty sure that I am using the jtag. The pins the wires are soldered to are labled with the standard pins of jtag. I think the thing at the top is the back of the connection to the lcd on the front.

A. There is absolutely no documentation.
B. There is absolutely no information.
C. I am really confused. I have researched the pullup resistors and :http://dangerousprototypes.com/docs/Mixed_voltage_interfacing_with_the_Bus_Pirate
but I cant figure out how to get 3v output. The 2.5 seems the same as all the others.

A. There is absolutely no documentation.
B. There is absolutely no information.

panasonic.encompass.com/shop/research_new/MSC/sm/KXTGA680B.pdf

Moral of the story: Dont give up and never say absolute.

thaGH05T wrote: Where did u find that??? And y did they spend this much time on a SVC manual for this device... All in all that's lucky as hell. Have u had a chance to play yet?

I was just googling around and found a manual for another one. I went back to the main site and there it was. What do you mean by "to play"? The manual does not mention jtag, at least by name, so I still dont know what to do. Also, I am still not sure how to get 3v with the bp - all the explanations for the pullup resistors only seem to be for other modes. I am starting to realize why you dont get a bus pirate for jtag.