General Question About Boot-up And Bricking

[juliodm]

Is this something you built? Or did they also provide you with a cable?
I thought that on the PL2 side, it should be a 24 pin setup, to fit in the EXT port?

[EDIT]
I made a schematic based on the one you posted, just to clarify the details ,because I don't know too much about it, it is http://www.jadium.com/DignSys_Schematic.jpg

I just want to make sure I got it correct, the last question I have is why have a transistor going to ground?

 

[juliodm]

Is this something you built? Or did they also provide you with a cable?
I thought that on the PL2 side, it should be a 24 pin setup, to fit in the EXT port?

[EDIT]
I made a schematic based on the one you posted, just to clarify the details ,because I don't know too much about it, it is http://www.jadium.com/DignSys_Schematic.jpg

I just want to make sure I got it correct, the last question I have is why have a transistor going to ground?

On the PL2 side, must all the grounds be connected? I just bought the ARM-JTAG cable, it's got all the correct components minus the ext port connector, but that basically just looks like a re-pinning situation. I could be horribly wrong though.

Does anyone know if it's just a re-pinning situation? If so, must all the jtag grounds be connected?

[EDIT]

OK. I found some drawings on WIKI describing the pinout config for EXT to ARM-JTAG cable ( 24way to 20way IDC connector). I worked up a cable for this and checked all my connections to make sure they are all properly grounded and that no short circuits exist. Using the posted JTAG-KIT software still doesn't see the unit. It does the same thing that the simple cable does. Basically just notices that something is connect, via the Device ID area, but still doesn't see the unit. What I'm wondering is if to use the more complicated ARM-JTAG cable it is required to use a full JTAG contects, meaning the full IDE software running on LINUX or at least Cygwin.... or something along those lines. Has any one been programing via JTAG, and if so what are you using for software?

The drawing I was refering to is:
http://wiki.gp2x.org/wiki/USB_Host_BoB_Schematic

The very first drawing and the very last one have all the details you need.... There is also this one:

http://microcontrollershop.com/Images/arm_...8407d56439345f9

Should you have the ARM-JTAG cable.

Thanks.
Juliodm.

 

[Manwe]

I've got "can't access tty: job control turned off" message after boot (using floppy, created by JTAG KIT.zip). Is it Ok, may I continue?

 

[juliodm]

I've got "can't access tty: job control turned off" message after boot (using floppy, created by JTAG KIT.zip). Is it Ok, may I continue?

As far as I understand that just means that you don't have a serial port to view the process afterwords, or it can't access the serial port, but you should be able to continue.

Please let me know what happens.
Also did you build your own cable using the simple png or did you buy the ARM-JTAG and mod it for the EXT port?

 

[Manwe]

I bought ARM-JTAG by Olimex

and connected 6 wires (4 data: TDO, TCK, TMS, TDI, 2 ground) to GP2X connector (taken from TV-cable). Also I tested all the pins of this connector (spent a lot of time and almost break my eyes) and posted results on Wiki: http://wiki.gp2x.org/wiki/EXT_Port_Connectors

Got the same bad thing:

Jatg - Using port 0x378
JTAG interface reset.
Device ID..0x00000000
CPU Not Support!

Tested with different LPT modes (Normal, EPP, etc.). Got the same result if GP2X turned off.

Idea: may be we need to connect PC's TDI to GP2X's TDO and PC's TDO to GP2X's TDI? If it means Test Data Input/Output... According to LPT pins scheme, pin 11 works as IN, and pin 5 as OUT. But in JTAG scheme LPT's pin 11 market as TDOutput, pin 5 as TDinput...
And what about +3V and TRST pins?

 

[Manwe]

Also did you build your own cable using the simple png or did you buy the ARM-JTAG and mod it for the EXT port?

I bought ARM-JTAG with 20 pin connector, cut this connector and solder 6 wires to GP2X's Ext TV connector. By the way, I tested ground wires on JTAG (4, 6... 22, 24) - they are all connected to each other inside the ARM-JTAG device, so I used 6th and 8th wires as a GND.

Update: I just resold TDO to TDI and TDI to TDO. The same result
Now, it all reminds me "Beavis and Butthead do America":
- Oh, I just figured something out!
- Really? What?!
- This sucks...

 

[Manwe]

This is the schematic I got from DignSys, if you want to check

For the 20-pin side, isn't strange that pins 1 and 2 are connected and there is no pin 3 on this scheme?
ARM-JTAG 20-pin Docs say:
PIN1 - Used to indicate the target's operating voltage to the debug tool.
PIN2 - Target voltage. may be used to supply power to the debug tool.
Couldn't we burn the GP2X, sending signal from pins 1 and 2 to GP2X's 20th and 21th pins?
And what about JTAG_TRST (pin 3 on arm-jtag, pin 18 on gp2x)?

UPDATE: Now, I soldered TRST and nRESET pins. Result is the same. Should I connect +3V now (last hope)?

 

[Fivelo]

Hello Chaps,

Thought I'd jump on this thread's bandwagon... Built a 'jtag' dongle as per Kaos' jpg (i.e. the one without an IC chip)

Results seem to be the same as others...

0x00000000 - when gp2x off
0xFFFFFFFFF - when on

It seems at least the jtag probe is recognising something there, but cannot start a connection.

I'm guessing it's cable related... Spent hours today putting it all together and am just a bit cheesed off

Any ideas?

 

[Fivelo]

For the sake of it... here are the images of the board itself (click for 1600x1200)

I haven't done any solder work in about 4-5 years so you'll have to bear with the nasty job on this!





<--- The most frustrating part of the whole dongle - apart from the fact that it doesn't work.

I have checked all of the strips and it doesn't look like there are any shorts, if anyone spots something please let me know!

NB. The trailing wire on the lower-right of the underside shot isnt making contact (and has since been removed anyway )

Well re-check everything tomorrow at some point.

 

[Manwe]

Fivelo, can you confirm this scheme of Ext connector?
http://wiki.gp2x.org/images/8/87/Gp2x_tv_cable_pins.jpg

 

[Fivelo]

Fivelo, can you confirm this scheme of Ext connector?
http://wiki.gp2x.org/images/8/87/Gp2x_tv_cable_pins.jpg

Hi Manwe,

That's what I worked it out as, using a magnifying glass & lamp, you can actually see the order the terminals go into the connecting part of the plug (guess you did the same!) Made the assumption that the top right was 24 as Kaos' scheme indicates that it's a ground - on my connector it's piggybacked to the screen of one of the audio/video cables - also whilst testing with a meter you can use it as ground and obtain ~3.3V when bridging the other terminals.

Haven't managed to re-check my bits yet but will report back if/when I discover anything - can anyone else confirm the non-IC version of the circuit works for them?

Many Thanks

 

[Manwe]

What I figured out, there are two types of JTAG interface.

One with a chip is "buffered" device, also called WIGGLER. It wouldn't works with "JTAG Tool". You need "OCD Commander" software or something like that.

Second type has a "simple" scheme, it should works with JTAG Tool.

First type of device need to be connected to GP2X with more contacts.

UPDATE: Finally, I fixed my GP2X. Here is a solution (soft, instruction): http://www.gp32x.de/board/index.php?showtopic=28876 (big thanks to Darkdave!). I used WIGGLER device, and obviously I soldered it to GP2X Ext connector right. That means, my pinouts schem was correct.

 

[juliodm]

I bought ARM-JTAG by Olimex

and connected 6 wires (4 data: TDO, TCK, TMS, TDI, 2 ground) to GP2X connector (taken from TV-cable). Also I tested all the pins of this connector (spent a lot of time and almost break my eyes) and posted results on Wiki: http://wiki.gp2x.org/wiki/EXT_Port_Connectors

Got the same bad thing:

Jatg - Using port 0x378
JTAG interface reset.
Device ID..0x00000000
CPU Not Support!

Tested with different LPT modes (Normal, EPP, etc.). Got the same result if GP2X turned off.

Idea: may be we need to connect PC's TDI to GP2X's TDO and PC's TDO to GP2X's TDI? If it means Test Data Input/Output... According to LPT pins scheme, pin 11 works as IN, and pin 5 as OUT. But in JTAG scheme LPT's pin 11 market as TDOutput, pin 5 as TDinput...
And what about +3V and TRST pins?

I connected all the ground pins on the 20pin connector becuase the instruction that came with is said that "All grounds must be connected." The vtref, according to this thread:
http://wiki.gp2x.org/wiki/Image:Bob_jtag.png
, is supposed to be connected to the +3v3 connector of the GP2X, becuase the jtag cable gets its power from the target board not the parallel port.

I think you might be correct about the TDI -> TDO cennection. I'm still getting the error you get as well. The only time the computer notices the device, is if the JTAG cable is disconnected completely, then you get an address of 0xFFFFFFFF. I'm going to try it tonight when I get home.

[EDIT]
I just noticed you fixed your GP2x..... You lucky !@#$%^& I'm at work and didn't bring my GP2X with me.... Can't wait to try what you did.... Thanks for the thread.

 

[Manwe]

I connected all the ground pins on the 20pin connector

Do you mean 20th pin of JTAG connected to 13th and 24th pins of GP2X? If yes, then it's all right.
Actually, there are a lot of "Ground" pins on the JTAG side, so you can use not only 20th pin, but also 4, 6, 8, 10, 12, 14, 16 and 18 - they are the same. It was more comfprtable for me to use pins 6 and 8.

Here is a scheme, you need to connect everything marked by green. TDO connected to TDO, TDI to TDI.

 

[juliodm]

I connected all the ground pins on the 20pin connector

Do you mean 20th pin of JTAG connected to 13th and 24th pins of GP2X? If yes, then it's all right.
Actually, there are a lot of "Ground" pins on the JTAG side, so you can use not only 20th pin, but also 4, 6, 8, 10, 12, 14, 16 and 18 - they are the same. It was more comfprtable for me to use pins 6 and 8.

Here is a scheme, you need to connect everything marked by green. TDO connected to TDO, TDI to TDI.

Dude...I'm so frustrated with this thing already..... All I get with the OCD Commander sofware is:
get_version : not yet initialized (01 : 06)

The timing thing can't be it.... I've tried it a million different ways. I know my connections are correct... so at this point, this stupid thing is about a minite away from getting slammed up at a wall.

What am I missing? Should I not have connected all the grounds like the instructions said to do for the ARM-JTAG connector?
I used both +3v3 connectors on the EXT port, because the wiki shows them connected, is that wrong?
They are pins 20 and 21.

Everything else is correct. I went over it atleast 6 times. Tomorrow, I'll resolder a whole new EXT port connector, just to do one final test, if it still doesn't work, I'm slaming this thing.

Oh, and my EXT connector looks nothing like the one you illustrated. I had to repin this thing from scratch, litterally pull all the pins out, and only put in the ones I needed, becuase the connected itself is commpletely different from your layout.

None the less though, counting from left to right, if your looking right into the EXT connector end, it starts at pin 24, right?

Like this:

24 1
________________________________________
| |
|_______|-|_______|-|_______|-|___________|

Where this bottom stuff ^ are the three slots on the bottom of the connector. The connector itself is facing you, the viewer.

Anyway, it's now 12:30 am here, and I have to go home. I don't own a PC, so I have to do this stuff from my brothers house.... this freaking thing really is a !@#$%^&*() load of trouble to deal with, especially considering I only had it for four days before trying that stupid 2.0 firmware and bricking it.

 

[Fivelo]

I'm pretty cheesed as well matey, I bricked my 2x within a week of it arriving - dodgy SD autobrick issue got me. It's only now that I've tried to sort it and the circuit doesn't work... Will possibly try a wiggler in the future though.

PS. No point in breaking anything, just stick it all in a drawer and forget about it for a couple of months

 

[Manwe]

counting from left to right, if your looking right into the EXT connector end, it starts at pin 24, right? The connector itself is facing you, the viewer.

Yes, it's all right.

my EXT connector looks nothing like the one you illustrated.

You need to draw your own scheme then. Use tester (voltmeter) with a needle and may be even magnifier glass... Is your connector taken from SamsungE810 or something like that? May be the contact with GP2X Ext port is not well and you need to fix connector's shape with a knife or a file?

All I get with the OCD Commander sofware is: get_version : not yet initialized (01 : 06)

It's true, I got the same messages many times before success.
Try This software from Olimex homepage (this picture shows setup details).
And, by the way, what ARM-JTAG you use? Manufactured by Olimex? If not, could you give a link to the product description?

The timing thing can't be it.... I've tried it a million different ways.

In my case, antivirus monitoring makes a problem. Try to close all the programms and residents.

Should I not have connected all the grounds like the instructions said to do for the ARM-JTAG connector?

Hmm, I need to know more about the ARM-JTAG device you using. If it has 20 pin connector, try to check wires 4, 6, 8, etc with a tester. They should be already connected to each other inside the device. By the way, the wire marked by red is 1, not 20. Right?

I used both +3v3 connectors on the EXT port, because the wiki shows them connected, is that wrong?

Don't sure. Better use only pin 20, like I did.

So, keep working - I spent 2 or 3 weeks before I've found the right way

Will possibly try a wiggler in the future though.

Try to find ARM-JTAG by Olimex then.

 

[juliodm]

Yeah, my ARM-JTAG cable is by Olimex. It's the wigler in the picture illustrated above. The OCD Commander software notices that the cable is connected, but that's it. It doesn't communicate with the Unit at all. I will solder a whole new connector today when I get home, after that I can't think of what else to do.

 

[Fivelo]

Thanks for all the investigation Manwe - much appreciated... You should put a guide on the wiki, would be great with all the necessary info in one place!

BTW Is this the same wiggler as yours?

Would still be nice if someone could confirm a positive result with the simple circuit though!

 

[juliodm]

Fivelo....I have a question regarding your simple circuit... Do you get an address of 0xFFFFFFFF or 0x00000000?
No matter what, I always get 0x00000000, I only get the F's if the cable is disconnected, which is different from Manwe... he actually got it to see the CPU, confirmed by the F's.

I'm going to keep trying to see if I can atleast get the F's, if so, then I should be able to re-flash this thing.