[HowTo] Jtag connection

Hello fellow M8 owners,


Hereby a dedicated topic on Jtag for M8/SE,
since i have not yet been able to test it myself on M8,
this first post will be rewritten in the near future to contain all important information.

So where to start?


Jtag Pinout :

Jtag cables :

The slowest working cable but easiest to build is the unbufffered cable.
You need a few resistors, a lpt plug (parallel port) and wires shorter then 15 cm to avoid noise and problems.

Unbuffered cable

JTAG-to-LPT mapping

TDI - DATA0 - pin 2
TDO - SELECT - pin 13
TMS - DATA2 - pin 4
TCK - DATA1 - pin 3

One of the most used cables is a buffered, a fabricated version will costs around 100~200 euro, a home made around 30~50 euro.
The price gives you faster data transport, ability for longer cables and less problems with noise or other.

Buffered cable (aka :wiggler)

JTAG-to-LPT mapping

TDI - DATA3 - pin 5
TDO - BUSY - pin 11
TMS - DATA1 - pin 3
TCK - DATA2 - pin 4
nSRST - DATA0 - pin 2
nTRST - DATA4 - pin 6

Software :

for windows users you can try OpenOcd or SJF6410 (samsung´s tool)
for Linux users try OpenOcd patch or Jtag Tools

So let us begin :-)
what we need,
witch prebuild cables can be used on m8,
how will we easily hold the pins to the M8 printboard.. etc.

There are some wiggler compatible JTAG interfaces, for example:
Development and Prototype boards and tools for PIC AVR and MSP430
(Click on ARM -> ARM JTAG)

The parallel port version is quite cheap (relative to the more than 100 $/€ devices):
ARM AVR MAXQ MSP430 PIC LOW COST DEVELOPMENT BOARDS PRICES PRICES

Here are some schematics for USB-to-JTAG self-build devices:
USB to JTAG Interface

Thanks man!
that seems very interesting, will have a look onto it!

Zeerix,

ive been looking to your links (thanks again)

Think those are interesting :

ARM-USB-TINY-H (+-40 euro)

Amontec JTAGkey-Tiny (+- 29 euro)


EP-OPENOCD-01 OpenOCD USB Adapter (+-39 euro)

The last one seems to have jtag ánd RS232 serial connection,
so for those who do not have it yet : interesting!

For myself i am thinking that the second one could be very interesting
(not to high pricetag)

The second one is nice and should work with OpenOCD, but the shipping cost is a cheek. It's > 20 € unless you are from switzerland.
The third one is cheaper if you consider shipping.
Check if you find a shop in your country and/or with low shipping.

i have to say, that i have no experience with jtag.... so how to do it? i mean, what do i have to do when a have a jtag adapter ?!

raoul

edit: can anyone verify that this works?
http://cgi.ebay.com/JTAG-programmer-...13169005r21573

Zeerix,
thanks again for the feedback!

At the moment i still do not have my m8 back,
so i am investigating my options at the moment
(the real shame is that i can not find a local shop in belgium that sells it
).

raangu, like you noticed it is been a while ago for me that i used jtag.
Normaly you should:

*connect jtag to m8
*connect to pc
*run the jtag software
=> then read and dump firmware to pc
=> or write firmware to m8
=> or debug software from m8

Now for the first 2 things any jtag cable should do since you only need
TDI - TDO - TMS - TCK connections
for the last one (debug) you need a jtag that can speak to the other pin´s.

Now to read/write the best thing we could have is openocd support (very often used ) or the sjf tools.

about the cable, i am also interested in itbut not sure if it fully supports m8, maybe best thing to do is contact the seller and ask if it would support the pins mentioned in the layout?

Guys,

could anyone of you with an m8 make a real size draw from the battery
and take note of the exact size & distances for the pinout?

example :

The idea after this :
then you would be able to make a 'fake' battery in plexiglass,
cut out a socket for the sim holder and drill holes where the jtag pinout is located. Then we could place pogo-pins in those holes and there would be no need for soldering jtag to M8.. since the "holder" would fit in like a battery and does not move around .. but can be removed anytime:-)

Good idea isnt? I am sure it makes life easier while jtagging M8!

For those who do not know pogo-pins, it are pressure pins, this lets you make a good contact with the M8 pcb.

example :

edit: can anyone verify that this works?
http://cgi.ebay.com/JTAG-programmer-...13169005r21573

some research shows it is a fake ulink, look here for the original.
I assume it would work for writing and debugging,
and the ebay one has a good price
(one of the cheapest incl. shippingcost for this kind device)

Features:

• Connects your PC or notebook's USBport to your target ARM hardware allowing you to debug C programmesrunning on the target board
• Allows you to debug and Flash programme ARM chips
• On-chip debugging via on-chip JTAG
• 28KB/s memory read/write speed
• 15KB/s Flash write speed
• Supports JTAG clock speeds of up to 1MHz
• Supports µVision IDE/Debugger
• Unlimited RAM breakpoints
• Supports ARM7, ARM9 and Cortex-M3 device families
• Supports multiple breakpoints
• LED indicator light and USB powered

i also found this one :
USB BUFFERED ALL IN ONE FTA JTAG PANSAT 3500/2500/2700

it does not have debugger, but same seller has pogo-pins..

EDIT

Main reason i did not yet buy new jtag is due the slow replacement proces for my M8. However this give me time to investigate jtag adapter.
I contacted reseller from the 3 jtag cables in the above post, but non of them answers my questions.
For now myself i am mostly interested the jtagkey-tiny.
I found the following schematic pdf : AESOP 6410 (by googling this way)
You will notice at the jtag pinout the following :
xRTCK - xTDO - xTDI - xTCK - xTMS - xTRSTn
So this means whe have on m8 pinout the following leftover:
CTS - NRESET - 3Volt (i do not count Ground with it)
Nreset is linked to the reset system in the SOC m8 uses
and cts seems to be found in the uart part.
so i wil investigate more soc schematics to be sure, but ATM i think if you have the first pinout i just mentionned you jtag should work perfect.


now will check this pdf

Hi, here are my findings on the M8 SE 8GB:

first my old measurement:

Originally Posted by Loonix

Well, here are my measurements



and again as text
01: 2,85
02: 0,04
03: 0,04
04: 0,04
05: 0,01
06: 0,80
07: 4,13 - 4,16
08: 3,06
09: 0,00 (GND? )
10: 3,04
11: 0,00
12: 0,35 - 0,38
13: 0,16 - 0,19
14: 3,04
15: 0,15 - 0,19
16: 3,04
17: 0,17 - 0,19
18: 0,00
19: 0,00 (had written down a 3,04 first but may have ben misstaken)
20: 0,29 - 0,36
21: 0,00
22: GND? (<- this is the pin i measured from)

and then my 'new' test measured from the - pole of the battery
01: 2,85v
02: 0,03v | 65 - 70K-Ohm
03: 0,03v | 65 - 70K-Ohm
04: 0,03v | 65 - 70K-Ohm
05: 0,00v | 39 - 41K-Ohm
06: 0,78v - 0,78v
07: 4,11v - 4,14v
08: 3,04v
09: 0,00v | 0,3-0,4ohm (GND? )
10: 3,02v
11: -0,01v | 10,5 - 10,7K-Ohm
12: 0,50v - 0,54v
13: 0,20v - 0,22v
14: 3,02v
15: 0,16v - 0,19v
16: 3,02v
17: 0,31v - 0,35v
18: -0,01v | 29,3Ohm
19: 3,02v (o.O the 0,00 value is gone, must have been a testing error or something)
20: 0,30v - 0,34v
21: -0,01v | 28,9 - 29,1Ohm
22: -0,01v 0,3-0,4Ohm (GND? )

Where i gave no Ohm value it was beyond the M-Ohm range.
I hope someone who knows his way around JTAG can do something with these values!

Great!
pin 1 - 8 - 10 - 14 - 16 - 19 could be the 3v jtag pin.

About the others, if someone with normal m8 would post his measurements about it, it would be an easy comparisation between them...

Hi!

Great stuff!
This tool and hardware (buffered LPT-adaptor) could also be very useful:
http://www.mt-system.ru/documents/sj...1_20071206.zip

As far as i remember there's also some modified SJF code at the aesop site.

Keep on hacking

scholbert

Originally Posted by evow04

About the others, if someone with normal m8 would post his measurements about it, it would be an easy comparisation between them...

No one that is willing to meassure the jtag pins to help loonix further?

i will see when i have freetime i will do a measurement

Here they are. Just our 8 pins in the order
SIM
1234
5678
measured with powerd on m8 over usb line against bat -

0 3.02 0.03 0.27-0.33 0
0 3.02 2.99-3.00 3.02 3.02

cool!
that is eliminating a few pins, but then again , there are a few that could be the same :s

I got 50 nude pogo-pins two weeks ago.
and I ordered some blank PCB today.
I'll try to make my connector this weekend.

Great! it is nice to see how professionally you are doing all this!
I am really interested in your progress and new findings once jtag works!

ps Banxian, did you manage to get usb (with ttl) on the M8SE working like on m8?

Hi, veterans! this pinout is just for M8 but is not for M8SE.
Anybody knows how to get the JTAG pinout for M8SE?
Thanks!

Two failed connector Board for M8 (not SE).
I think I can make a fine borad this week.

@banxian
big up!