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JTAG debugging options

Started by Sean January 2, 2006
Hello All,

I have seen a lot of talk around about Wiggler-based JTAG debugger boards,
which can be built for < $1, and I see several commercial JTAG debugging
pods that are > $1000. What is it that these things do that you can't do
with a simple wiggler interface? I.e. for most intents and purposes what
can you not do with a wiggler interface?

Even the original maker of wiggler charges > $150 for this board, which can
be built for like $1. What's the deal there?

-- Sean


An Engineer's Guide to the LPC2100 Series

That's not even a realistic comparison, if I gave you <$100 would
you/could you supply me with 100 wigglers? Are you even considering that
the newer ones are USB based and much more complicated than a simple
parallel port device? If for instance an engineers time is valued at
$100 an hour, could he produce a one-off "professional finish" wriggler
for less then $150? That's right, why bother!

Have you ever been involved in marketing? A humble can of beans may only
contain a few cents worth of beans but I'm sure you pay a lot more than
that for it quite happily. You could save yourself some money and grow
them yourself, but isn't there always a cost involved in everything we do?

BTW, I have never needed to use ARM wrigglers myself.

*Peter*

Sean wrote:
> I have seen a lot of talk around about Wiggler-based JTAG debugger boards,
> which can be built for < $1, and I see several commercial JTAG debugging
> pods that are > $1000. What is it that these things do that you can't do
> with a simple wiggler interface? I.e. for most intents and purposes what
> can you not do with a wiggler interface?
>
> Even the original maker of wiggler charges > $150 for this board, which can
> be built for like $1. What's the deal there?




Easy, Tiger :) Yes... I understand that time = money.

Perhaps I have misunderstood something. Is this not a Wiggler-compatible
interface?

http://www.micronix.ca/sbc213x_main.htm
http://www.micronix.ca/catalog/product_pages/images/JTAG02_SCH_011.jpg Perhaps I should rephrase my original question:

What JTAG debugging options are there, and what's the difference between
the ~$150 and > $1000 board options?

-- Sean At 09:22 PM 1/2/2006, you wrote:
>That's not even a realistic comparison, if I gave you <$100 would
>you/could you supply me with 100 wigglers? Are you even considering that
>the newer ones are USB based and much more complicated than a simple
>parallel port device? If for instance an engineers time is valued at
>$100 an hour, could he produce a one-off "professional finish" wriggler
>for less then $150? That's right, why bother!
>
>Have you ever been involved in marketing? A humble can of beans may only
>contain a few cents worth of beans but I'm sure you pay a lot more than
>that for it quite happily. You could save yourself some money and grow
>them yourself, but isn't there always a cost involved in everything we do?
>
>BTW, I have never needed to use ARM wrigglers myself.
>
>*Peter*
>
>Sean wrote:
> > I have seen a lot of talk around about Wiggler-based JTAG debugger boards,
> > which can be built for < $1, and I see several commercial JTAG debugging
> > pods that are > $1000. What is it that these things do that you can't do
> > with a simple wiggler interface? I.e. for most intents and purposes what
> > can you not do with a wiggler interface?
> >
> > Even the original maker of wiggler charges > $150 for this board, which
> can
> > be built for like $1. What's the deal there? >----------
>>Yahoo! Terms of Service. >----------




Sean pointed out that the Macraigor Wiggler is $150 whilst the
Olimex clone is $19 and asks "what's the deal here?"

Open up a wiggler and you'll see that it's a cheap level-shifter
chip and a transistor built into a DB-25 shell. Admittedly, $19
seems more like a fair price, but Olimex didn't write the OCDRemote
and OCDCommander software and didn't have to ammortize any software
development (Macraigor does). Macraigor probably provides more
telephone support if the customer has trouble getting it to work.

Even the fastest wiggler baud rate is slow in comparison to the
newer USB and Ethernet JTAG debuggers. This is not obvious in short
demo programs, but painful if you are downloading a very large
program.

I worry about myself and others relying on the Macraigor OCDRemote
JTAG program that interfaces GDB to the JTAG pins. OCDRemote is NOT
open-source. Macraigor allows free downloads of the OCDRemote
executable but the source code has always been proprietary. They
could withdraw this "freebie" at any time.

We need two things. A reasonably priced USB JTAG debugger supported
by a true "open-source" GDB/JTAG driver. Until then, the debugging
situation will remain tenuous, at best (for those on limited
budgets).

Cheers,
James P. Lynch


Sean wrote:
> Easy, Tiger :) Yes... I understand that time = money.
Since I'm not speaking to you face to face I just cut to the chase :) > Perhaps I have misunderstood something. Is this not a Wiggler-compatible
> interface?
>
> http://www.micronix.ca/sbc213x_main.htm
> http://www.micronix.ca/catalog/product_pages/images/JTAG02_SCH_011.jpg > Perhaps I should rephrase my original question:
>
> What JTAG debugging options are there, and what's the difference between
> the ~$150 and > $1000 board options?

The JTAG-02 is only CAD $35, I'm not sure where you find the $150
option. The Keil ULINK (USB) is only $199 but I'm not aware of any
>$1000 options. As James pointed out, the basic hardware is
straightforward but the driver software is a different story altogether.

*Peter*



Ok, the one I saw was

http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG/Macraigor/BDM-JTAG_Macraigor_usbDemon.htm

or

http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG/Macraigor/BDM-JTAG_Macraigor_Raven.htm

both 818EUR

And their wiggler is 188 EUR. Yes, most others I see are in the $150 -
$300 range.

I'm just trying to understand here. I can see how originally there were
few (expensive) options, and there was a lot of design and support and
software creation necessary, so yes, it was expensive. However from the
point of view of anyone who is starting a design, be it a starving student
or a multinational corporation, what do the expensive emulators do that I
can't do with a $1 DIY one? Can I get by with a DIY one, or should I
actually fork out the cash for the name-brand ones? Let's assume that I
need to do non-trivial debugging here.

I too am a fan of alternate methods for debugging, or creating modules on
the PC and then porting them, or loggers, or serial port dumps, however
there are times when having an ICE makes it a lot easier to figure out.

Thanks for the advice,

-- Sean At 10:35 PM 1/2/2006, you wrote:
>Sean wrote:
> > Easy, Tiger :) Yes... I understand that time = money.
>Since I'm not speaking to you face to face I just cut to the chase :) > > Perhaps I have misunderstood something. Is this not a Wiggler-compatible
> > interface?
> >
> >
> <http://www.micronix.ca/sbc213x_main.htm" target="_blank" rel="nofollow">http://www.micronix.ca/sbc213x_main.htm>http://www.micronix.ca/sbc213x_main.htm
> > http://www.micronix.ca/catalog/product_pages/images/JTAG02_SCH_011.jpg
> >
> >
> > Perhaps I should rephrase my original question:
> >
> > What JTAG debugging options are there, and what's the difference between
> > the ~$150 and > $1000 board options?
>
>The JTAG-02 is only CAD $35, I'm not sure where you find the $150
>option. The Keil ULINK (USB) is only $199 but I'm not aware of any
> >$1000 options. As James pointed out, the basic hardware is
>straightforward but the driver software is a different story altogether.
>
>*Peter* >
>----------
>>Yahoo! Terms of Service. >----------





This is a very good point: why are they offering their software for free,
knowing full well that other people are using it on competitor's hardware?

Yes, baud rates are slower over parallel, although you can get > 1mbit/sec
on the parallel port itself, perhaps only 25KB/sec when using wiggler, but
even there, even with a rather large code size of 512KB, this is only 20
seconds to download... For most debugging scenarios you won't need to
download the full size anyway, and if you split your program into modules
you can get by with only debugging a module at a time, which means you only
need to load a few dozen KB at a time?

-- Sean

At 10:21 PM 1/2/2006, you wrote:
>Sean pointed out that the Macraigor Wiggler is $150 whilst the
>Olimex clone is $19 and asks "what's the deal here?"
>
>Open up a wiggler and you'll see that it's a cheap level-shifter
>chip and a transistor built into a DB-25 shell. Admittedly, $19
>seems more like a fair price, but Olimex didn't write the OCDRemote
>and OCDCommander software and didn't have to ammortize any software
>development (Macraigor does). Macraigor probably provides more
>telephone support if the customer has trouble getting it to work.
>
>Even the fastest wiggler baud rate is slow in comparison to the
>newer USB and Ethernet JTAG debuggers. This is not obvious in short
>demo programs, but painful if you are downloading a very large
>program.
>
>I worry about myself and others relying on the Macraigor OCDRemote
>JTAG program that interfaces GDB to the JTAG pins. OCDRemote is NOT
>open-source. Macraigor allows free downloads of the OCDRemote
>executable but the source code has always been proprietary. They
>could withdraw this "freebie" at any time.
>
>We need two things. A reasonably priced USB JTAG debugger supported
>by a true "open-source" GDB/JTAG driver. Until then, the debugging
>situation will remain tenuous, at best (for those on limited
>budgets).
>
>Cheers,
>James P. Lynch >
>----------
>>Yahoo! Terms of Service. >----------




--- In lpc2000@lpc2..., Sean <embeddedrelated@w...> wrote:
>
>
> Ok, the one I saw was
http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG
/Macraigor/BDM-JTAG_Macraigor_usbDemon.htm
>
> or
http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG
/Macraigor/BDM-JTAG_Macraigor_Raven.htm
>
> both 818EUR
>
> And their wiggler is 188 EUR. Yes, most others I see are in the
$150 -
> $300 range.
>
> I'm just trying to understand here. I can see how originally
there were
> few (expensive) options, and there was a lot of design and support
and
> software creation necessary, so yes, it was expensive. However
from the
> point of view of anyone who is starting a design, be it a starving
student
> or a multinational corporation, what do the expensive emulators do
that I
> can't do with a $1 DIY one? Can I get by with a DIY one, or
should I
> actually fork out the cash for the name-brand ones? Let's assume
that I
> need to do non-trivial debugging here.

Well then, if you want to do non-trivial debugging, you'll certainly
hate Insight->OCD Remote->Wiggler clone. As James Lynch points out
in his excellent tutorial, there are days when it just won't work.
To be blunt, it sucks. It isn't worth the aggravation to get it
working; printf works better.

Now, Tom Walsh is more than happy with his high dollar solution
(Abatron BDI2000) and if I were doing this for money, I would buy
the same interface he has. If I could find a distributor in the
US...

And, if the US$ wasn't complete worthless when converted to British
Pounds, I might consider the Rowley CrossConnect package.

Richard
>
> I too am a fan of alternate methods for debugging, or creating
modules on
> the PC and then porting them, or loggers, or serial port dumps,
however
> there are times when having an ICE makes it a lot easier to figure
out.
>
> Thanks for the advice,
>
> -- Sean > At 10:35 PM 1/2/2006, you wrote:
> >Sean wrote:
> > > Easy, Tiger :) Yes... I understand that time = money.
> >Since I'm not speaking to you face to face I just cut to the
chase :)
> >
> >
> > > Perhaps I have misunderstood something. Is this not a Wiggler-
compatible
> > > interface?
> > >
> > >
> >
<http://www.micronix.ca/sbc21" target="_blank" rel="nofollow">http://www.micronix.ca/sbc213x_main.htm>http://www.micronix.ca/sbc21
3x_main.htm
> > >
http://www.micronix.ca/catalog/product_pages/images/JTAG02_SCH_011.jp
g
> > >
> > >
> > > Perhaps I should rephrase my original question:
> > >
> > > What JTAG debugging options are there, and what's the
difference between
> > > the ~$150 and > $1000 board options?
> >
> >The JTAG-02 is only CAD $35, I'm not sure where you find the $150
> >option. The Keil ULINK (USB) is only $199 but I'm not aware of any
> > >$1000 options. As James pointed out, the basic hardware is
> >straightforward but the driver software is a different story
altogether.
> >
> >*Peter*
> >
> >
> >
> >----------
> >>Yahoo! Terms of Service.
> >
> >
> >----------
>




----- Original Message -----
From: "Sean" <embeddedrelated@embe...>
To: <lpc2000@lpc2...>
Sent: Tuesday, January 03, 2006 4:21 AM
Subject: Re: [lpc2000] JTAG debugging options >
> Ok, the one I saw was
>
> http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG/Macraigor/BDM-JTAG_Macraigor_usbDemon.htm
>
> or
>
> http://www.gwmicros.com/public_html/pages/products/iproducts/BDM_JTAG/Macraigor/BDM-JTAG_Macraigor_Raven.htm
>
> both 818EUR
>
> And their wiggler is 188 EUR. Yes, most others I see are in the $150 -
> $300 range.
>
> I'm just trying to understand here. I can see how originally there were
> few (expensive) options, and there was a lot of design and support and
> software creation necessary, so yes, it was expensive. However from the
> point of view of anyone who is starting a design, be it a starving student
> or a multinational corporation, what do the expensive emulators do that I
> can't do with a $1 DIY one? Can I get by with a DIY one, or should I
> actually fork out the cash for the name-brand ones? Let's assume that I
> need to do non-trivial debugging here.
>
> I too am a fan of alternate methods for debugging, or creating modules on
> the PC and then porting them, or loggers, or serial port dumps, however
> there are times when having an ICE makes it a lot easier to figure out.

A DIY one will be fine. I designed a PCB for one that may easily be made at
home with rudimentary facilities (artwork in jtag.zip in the Files area).
It'll probably take a couple of hours to make the PCB and get it working.

I already had a genuine Macraigor Wiggler and mine works at higher speeds
than the real thing; my PCB layout is better. I've also got a Rowley
CrossConnect (99 GBP) with a USB connection to the PCB, and that works very
well. USB is more convenient than a parallel port connection, and faster.

Amontec sells their Chameleon interface, which is based on a reconfigurable
CPLD. It can emulate a Wiggler or Raven, as well as lots of other
interfaces, including JTAGs for Xilinx and Altera parts. I've got one of
those, as well. Worth getting if you want to play with FPGAs and other JTAG
MCUs.

Leon


On 2 Jan 2006 at 23:25, Sean wrote:

>
> This is a very good point: why are they offering their software for
> free, knowing full well that other people are using it on competitor's
> hardware?

The advertising value they get is immense. Anybody who has used a
wiggler or wiggler clone would at least give their more sophisticated
models a look if they are considering getting something a bit better
than a wiggler.

> Yes, baud rates are slower over parallel, although you can get >
> 1mbit/sec on the parallel port itself, perhaps only 25KB/sec when
> using wiggler, but even there, even with a rather large code size of
> 512KB, this is only 20 seconds to download... For most debugging
> scenarios you won't need to download the full size anyway, and if you
> split your program into modules you can get by with only debugging a
> module at a time, which means you only need to load a few dozen KB at
> a time?

The biggest issue with using the wiggler, is that it is temperamental. It works
quite nicely when it works, but there are days when it just refuses to work - normally
when you actually need it. Any JTAG interface where the JTAG signal timing is
independant of the PC hardware/software used are going to be more stable.

An open hardware / open source JTAG interface with USB / ethernet interface
would be great. Designing and building the hardware is not such a big problem.
Writing the software is the biggest issue for such a project.

Regards
Anton Erasmus > -- Sean
>
> At 10:21 PM 1/2/2006, you wrote:
> >Sean pointed out that the Macraigor Wiggler is $150 whilst the
> >Olimex clone is $19 and asks "what's the deal here?"
> >
> >Open up a wiggler and you'll see that it's a cheap level-shifter chip
> >and a transistor built into a DB-25 shell. Admittedly, $19 seems more
> >like a fair price, but Olimex didn't write the OCDRemote and
> >OCDCommander software and didn't have to ammortize any software
> >development (Macraigor does). Macraigor probably provides more
> >telephone support if the customer has trouble getting it to work.
> >
> >Even the fastest wiggler baud rate is slow in comparison to the
> >newer USB and Ethernet JTAG debuggers. This is not obvious in short
> >demo programs, but painful if you are downloading a very large
> >program.
> >
> >I worry about myself and others relying on the Macraigor OCDRemote
> >JTAG program that interfaces GDB to the JTAG pins. OCDRemote is NOT
> >open-source. Macraigor allows free downloads of the OCDRemote
> >executable but the source code has always been proprietary. They
> >could withdraw this "freebie" at any time.
> >
> >We need two things. A reasonably priced USB JTAG debugger supported
> >by a true "open-source" GDB/JTAG driver. Until then, the debugging
> >situation will remain tenuous, at best (for those on limited
> >budgets).
> >
> >Cheers,
> >James P. Lynch
> >
> >
> >
> >
> >
> >
> >----------
> >>Yahoo! Terms of Service.
> >
> >
> >---------- >
>
> Yahoo! Groups Links >

--
A J Erasmus