What Is Jtag?-joint Test Action Group-fag

Admin عدد المساهمات : 3267 تاريخ التسجيل : 17/11/2007

1.What is JTAG ?

1.1.Where can I get more info about JTAG?

Future JTAG reading:
Here is a download of
a 77-page JTAG tutorial from ASSET InterTech. If you'd like a hardcopy
of this book sent to you, go to this page and provide your mailing
address. You can find more information on JTAG at the ASSET InterTech
website

Link to pdf of tutorial
http://www.asset-intertech.com/pdfs/...orial_2007.pdf

Link to mailing address form
http://www.asset-intertech.com/regis...cfm?lnk=primer

Link from ASSET to more JTAG resources
http://www.asset-intertech.com/bound...leadership.cfm

Also:

http://www.inaccessnetworks.com/proj...tag-intro.html

http://www.engr.udayton.edu/faculty/...tag/jtag1.html

http://www.circuitcellar.com/library...99/c109r12.asp

AVR specific
http://www.circuitcellar.com/library...d143/index.htm

Boundary-Scan Tutorial
http://www.ezytech.com/asset/pdfs/bo...n_tutorial.pdf

Very good repository of JTAG references:
http://uclinux.home.at ( got to "JTAGS" directory)
1.2.May I use JTAG interface for remote debugging?

YES , of course – it is what JTAG for!

Sometimes different terms are used, as following:

OCD ( On Circuit Debugger)
ICE (In Circuit Emulator)
BDM (Background Debug Mode)

Future reading
http://www.ocdemon.net/zenofbdm.pdf
1.3.May I use JTAG interface for FLASH memory programming?

YES , of course – it is what JTAG for!

1.4.What part of JTAG standard is CPU agnostic?

JTAG specification is in Std IEEE 1149.1 (costs about $100). I don't
have it. Please search at internet for some JTAG related documents.
This is good: http://www-s.ti.com/sc/psheets/ssya002c/ssya002c.pdf

JTAG state machine [insert here]
JTAG standard signal [insert here]
That's all! You just have to write software to go through the states of JTAG FSM (here is the state diagram of this FSM: http://www.inaccessnetworks.com/proj...hine-large.png).
TCK and TMS are used to go through the states of FSM. And TDI is used
to serially send through this interface your commands and data to JTAG
controller on the IC (in your case, to the ARM uC) and read back reply
through the TDO pin. The only problem is that some companies do not
open all details about available custom JTAG commands (JTAG standard
defines only 2 necessary commands: EXTEST and SAMPLE and some optional
commmands like INTEST, BIST and others). For example, Texas Instruments
do not give an access to the description of commands that are used for
In-Circuit Debugging of their TMS DSPs. Instead of, they sell this JTAG
ICD with simple software for about 1000$!!! Nice business - such a
price for 4 wires and some I/O ICs! ;-)

1.5.What CPUs architectures have a build-in JTAG support?

AVR060: JTAG ICE Communication Protocol for 8-bit AVR Microcontrolers
http://www.atmel.com/atmel/acrobat/doc2524.pdf
ATmega128:JTAG Interface and On-chip Debug System, Page 245 to 272
http://www.atmel.com/atmel/acrobat/doc2467.pdf
Schematics for High-Speed BDM Pod for the Coldfire CPU
http://www.fortunecity.com/campus/ps...93/bdm/bdm.htm

ARM7TDMI build in ICE (see Chapter 5 and Appendix B)
http://www.arm.com/pdfs/DDI0210B_7TDMI_R4.pdf

1.6.JTAG support for ARM architecture?

ARM7TDMI build in ICE (see Chapter 5 and Appendix B)
http://www.arm.com/pdfs/DDI0210B_7TDMI_R4.pdf

1.7.What is a usual JTAG header pin-out?

More pin-outs see at http://www.ocdemon.net/pinouts.pdf
1.7.1.14-pin JTAG header

Usual pin-out for 14-pin JTAG header (often used for ARM)

1 -Vddh (+3.3v)
2 - Vss (ground)
3 - nTRST
4 - Vss (ground)
5 - TDI
6 -Vss (ground)
7 - TMS
8 -Vss (ground)
9 - TCK
10-Vss (ground)
11- TDO
12-nRESET (optional)
13- Vddh (+3.3v)
14-Vss (ground)

1.7.2.20-pin JTAG header

Usual pin-out for 20-pin JTAG header (sometimes used for ARM)
1 - Vddh (+3.3v)
2 - Vddh (+3.3v)
3 - nTRST
4-Vss (ground)
5 - TDI
6-Vss (ground)
7 - TMS
8-Vss (ground)
9 - TCK
10-Vss (ground)
11 --------
12-Vss (ground)
13 –TDO
14-Vss (ground)
15 – nRST
16-Vss (ground)
17---------
18-Vss (ground)
19---------
20-Vss (ground)

1.7.3.8-pin JTAG header

Usual pin-out for 8-pin JTAG header, often used for PLD programming
1 – vddh (+3.3v)
2 – TDO
3 – TDI
4 – nTRST
5
6 – TMS
7 – vss (ground)
8 – TCK

2.What hardware do I need to connect to the JTAG interface?

2.1.Where to buy JTAG adapter?

JTAG adapter can be purchased from multiple sources. Many embedded
OS companies ( WindRiver and similar) are offering JTAG adapters with
their debuggers and other testing software. Unfortunately, these
packages are very expensive – usually a few thousand dollars.

Following companies have more or less reasonable product offerings

(Disclaimer: author(s) of this chapter have no direct commercial
interest whatsoever in following companies.(Note: please do an
appropriate disclaimer for new submissions if otherwise ))
2.1.1.Macraigor Systems LLS

Macraigor Systems (http://www.ocdemon.net/)
is known as a vendor of reasonably inexpensive JTAG solutions. Their
Wiggler ( $150) parallel port adapter became de-facto a standard for a
simple buffered JTAG adapters. Due its simplicity , Macraigor Wiggler
is easily cloned by home-made JTAGs ( see more in “How to build JTAG” section)

Macraigor Systems is offered a FLASH programming software ( $500), a free simple On-Chip-Debugger (OCD Commander - http://www.ocdemon.net/ocd_dbgr.exe ) and a free LibRemote daemon for interfacing GDB/Insight remote debuggers ( see CYGWIN version at http://www.ocdemon.com/Windows98NT/A...stallation.exe ).

2.1.2.AZ-Electronics

AZ_Electronics (http://az-electronics.com/item9.htm ) is offering a cheap ( $35) parallel port JTAG adapter.

2.1.3.JtagConnection

JtagConnection (http://www.jtagconnection.com/index.php) is offering a cheap ( $35-40) parallel port JTAG adapter.

2.1.4.Rowley Associates

Rowley Associates introduce its CrossConnect – USB 1.1 fast JTAG adapter with retail price of about £150.
http://www.rowley.co.uk/

2.1.5.Amontec

Amontec sells a very nice programmable JTAG dongle, the Chameleon POD.
It can be programmed as Macraigor Wiggler or Raven.
http://www.amontec.com/chameleon.shtml

2.2.How to build JTAG adapter?

http://www.lart.tudelft.nl/projects/..._schematic.pdf
http://www.lart.tudelft.nl/projects/jtag/

2.2.1.Macraigor Wiggler compatible JTAG adapters

http://jtag-arm9.sourceforge.net/circuit.txt

http://bh.udev.org/filez/wireless/sa...510-ver0.2.pdf

2.2.2.LART JTAG

http://www.lart.tudelft.nl/projects/..._schematic.pdf

http://www.lart.tudelft.nl/projects/..._Rev_X1.tar.gz (Gerber file )
2.2.3.Xilinx JTAG

http://www.plis.ru/pic/zip/JTAG_cable.pdf

A simplified non-buffered version may be found at http://axl.freeyellow.com/iPAQ/jtag.htm . Please note that not-buffered JTAG adapter has an increased posibility to damage your host’s parallel port circuit.

2.2.4.ALTERA JTAG

ALTERA ByteBlast Parallel Port Adaptor
http://www.altera.com/literature/ds/dsbyte.pdf

2.2.5.ColdFire BDM Pod

I've made by myself an High-Speed BDM Pod for the Coldfire CPU, i've
found the schematics at
http://www.fortunecity.com/campus/ps...93/bdm/bdm.htm

2.2.6.Serial Jtag

http://mspgcc.sourceforge.net/jtagF14x.pdf
http://cvs.sourceforge.net/viewcvs.py/mspgcc/jtag/

http://mspgcc.sourceforge.net/manual...html#pyserjtag

3.What software do I need to use JTAG for remote debugging?

3.1.OCD Commander

OCD Commander - http://www.ocdemon.net/ocd_dbgr.exe
3.2.LibRemote for GDB

CYGWIN version at http://www.ocdemon.com/Windows98NT/A...stallation.exe

How to use LibRemote for ARM under CYGWIN environment:

TBD
TBD
TBD
TBD

4.What software do I need for FLASH memory programming?

4.1.Intel JFlash

Original Intel program for memory flash for SA1110 dev board. Contains source for Windows utility JFlash.
http://www.intel.com/design/strong/s...ashKit_V12.exe

Works with LART JTAG parallel port adapter (see above).
4.2.JFlash for linux

As a part of LART project, this is a Linux port of Intel JFlash utility.
http://www.lart.tudelft.nl/projects/...h-linux.tar.gz

Some modifications and corrections from TuxScreen hacking project
http://cvs.sourceforge.net/viewcvs.py/tuxscreen/jflash/

Works with LART JTAG parallel port adapter (see above).
5.Open Source JTAG Software Projects

5.1.ARMTOOL from MIDORI distribution

Erwin Authried is maintaining Embedded Linux & uClinux distribution (MIDORI distribution - http://cvs.home.at/midori/ ) . ARMTOOL is a small, but important utility in this distribution (some part of the source).

ARMTOOL (http://cvs.home.at/midori/sources/armtool/)
is a very simple JTAG monitor that supports upload and download a
binary image into memory and its execution. ARMTOOL is ARM7TDMI
specific (some part of code is derived from GDBICE
project), but may work with some of ARM9 cores (to be tested). Current
version supports JTAG adapters compatible with Macgraigor Wiggler,
Altera ByteBlasterMV and Xilinx Parallel port JTAG adapter.

In addition to ARMTOOL, MIDORI distribution includes patch for
GDB/Insight debugger to use JTAG interface for remote debugging.

Also, BOOTLOADER module contain a simple ARM program which maybe used
for flashing a new image into FLASH memory ( FLASHPROG).

5.1.1.HOWTO compile ARMTOOL

(outside of full MIDORI source tree)
http://hri.sourceforge.net/tools/armtool.html
Petr Novak wrote a patch that extends armtool capabilities: patch README (updated 20/Jan/2004)

5.1.2.HOWTO compile FLASHPROG

(outside of full MIDORI source tree)

5.1.3.HOWTO compile GDB/Insight

(outside of full MIDORI source tree)

5.2.GDBICE

GDBICE (http://sourceforge.net/projects/gdbice/)
is and open source SW/HW project by Ramon Longo users.sourceforge.net>. It is an attempt to design JTAG remote
debugging for ARM7TDMI cores. Unfortunately, this project was not pass
above an initial “proof-of-concept” implementation and not supported
anymore.
However, this project’s source code maybe useful for someone who need a crash introduction into JTAG and its ARM specifics.

5.3.JTAG from OpenWinCE

http://openwince.sourceforge.net/jtag/
by Marcel Telka

5.4.JTAG-ARM9

http://jtag-arm9.sourceforge.net/
by Simon Wood

5.5.FreeICE

http://savannah.nongnu.org/projects/freeice
by Armand ten Doesschate a.doesschate@hccnet.nl

5.6.Ascensit JTAG for ARM7TDMI

http://www.ascensit.com/developers/atmel_eb55/main.php3
by Ascensit
by Christian Pellegrin

5.7.JTAGER

http://jtager.sourceforge.net/

5.8.IANJTAG

http://www.inaccessnetworks.com/projects/ianjtag
May be related to the FreeIce

Admin عدد المساهمات : 3267 تاريخ التسجيل : 17/11/2007

FIRMWARE>

n. Executable software that is stored within a ROM.

USAGE: This term is interchangeable with embedded software and sometimes is used even when the executable is not stored in ROM.

FLASH>

1. v. To download new firmware into a flash memory. A bootloader
typically facilitates this process by communicating with a program on
the host, erasing the flash memory, and writing the new code. The
sector of the flash memory that contains the bootloader's code must not
be overwritten in the process.

FLASH MEMORY>

n. A RAM-ROM hybrid that can be erased and rewritten under software
control. Abbreviated flash. Flash is an in-circuit programmable
nonvolatile memory segmented into blocks called sectors. Each sector
can be individually erased, then the data within it rewritten. Flash
memory is common in systems that require nonvolatile data storage at
very low cost. In some cases, a large flash device can be used instead
of a disk drive. Although there is a theoretical limit to the number of
times a flash memory can be erased and rewritten successfully, this
limit is seldom reached in practice.

Admin عدد المساهمات : 3267 تاريخ التسجيل : 17/11/2007

Check out OpebOCD for those interested in open source free JTAG debugging tools

http://openocd.berlios.de/web/

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