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ISO Maple JTAG details

(7 posts) (2 voices)

Started 5 years ago by importer
Latest reply from poslathian

importer
Inactive

on Thu 24 of Dec., 2009 09:33 EST, by LarryP

Greetings all,

I note from the photos of Maple that the footprint for its JTAG connector is 8 pins (2x4 header), not the 2x10 pinout used for most ARM boards. So, I have two key questions:

Which JTAG devices are known to work with the Maple? (Mfgr/Model#)

If a custom cable is needed between the JTAG device and the Maple, which JTAG-device pins go to which Maple-Jtag-connector pins?

Thanks in advance,

Larry

================

Some details:

Typical JTAG used for ARM/Cortex CPUs:
http://www.olimex.com/dev/images/arm-jtag-layout.gif

Essential JTAG signals: http://en.wikipedia.org/wiki/Joint_Test_Action_Group#Electrical_characteristics

Posted 5 years ago #
importer
Inactive

on Mon 28 of Dec., 2009 16:58 EST, by poslathian

Larry,
See the bottom of this post - http://leaflabs.com/tiki-view_forum_thread.php?comments_parentId=7&topics_offset=3&topics_sort_mode=lastPost_desc&forumId=4 - where we had a similar discussion. Ill track down a schematic of the pin remapping. You should be able to back it out of the Maple Schematic, which is viewable using the open source Eagle program. I'll also look into compiling these to pdf.

>
> Some details:
>
> Typical JTAG used for ARM/Cortex CPUs:
> http://www.olimex.com/dev/images/arm-jtag-layout.gif
>
> Essential JTAG signals: http://en.wikipedia.org/wiki/Joint_Test_Action_Group#Electrical_characteristics

Posted 5 years ago #
importer
Inactive

on Wed 17 of Feb., 2010 19:15 EST, by oooop

>Maple Schematic, which is viewable using the open source Eagle program

Eagle is proprietary software and uses proprietary and closed file formats.

There is a freeware version of Eagle which limits boards to 4 x 3.2 inches and allows viewing.

There are many true Free and Open Source EDA alternatives. Please do not mistake Eagle for being Open.

gEDA: http://www.gpleda.org/
KiCAD: http://kicad.sourceforge.net/
TinyCAD: http://tinycad.sourceforge.net/
electric: http://www.staticfreesoft.com/

Posted 5 years ago #
importer
Inactive

on Wed 17 of Feb., 2010 19:17 EST, by oooop

Why not use the Cortex JTAG Debug connector developed by ARM?

http://www.keil.com/peripherals/coresight/connectors.asp

Posted 5 years ago #
importer
Inactive

on Sun 21 of Feb., 2010 03:19 EST, by poslathian

If you do use the olimex jtag, which we use, youll have the benefit of our JTAG toolchain in the repo. In leaflabs/build_box, leaflabs/bootloader, and leaflabs/library

$> make program

automagically spins up openocd with the right config file to work with that JTAG. If you have your own toolchain and your own JTAG, theres no reason you couldnt use it. It just might take longer ;)

By the way, we agree about Eagle. Were committed to staying away from propietary formats and software and are currently trialling Kicad, the free software for circuits and layout.

Posted 5 years ago #
importer
Inactive

on Tue 02 of Mar., 2010 16:26 EST, by oooop

The Olimex JTAG is OpenOCD-compatible so your board can be connected to any OpenOCD-compatible JTAG using flying wires, right?

If you expose all the JTAG pins (TMS, TCK, TDO, TDI, RESET) then yes. I wanted to check but cannot find the schematic in your Google repository (http://code.google.com/p/leaflabs/source/checkout).

Posted 5 years ago #
poslathian
LeafLabs

You are correct, and we do expose all the necessary lines. Our schematics are located here:
http://code.google.com/p/leafhw/

Posted 5 years ago #

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