JTAG schematics & H-JTAG not connecting

matiasnabarro · ‎2007-11-16

Posted on November 16, 2007 at 10:14

matiasnabarro · ‎2007-11-05

Posted on November 05, 2007 at 15:59

Hello: attached is one JTAG interface prototype I've built, intended to work with any ARM. I've tested it with H-JTAG & STR751 and the software can't connnect to the ARM. Is it something wrong with the schematics or someone has any hints regarding first steps with ARMs ?

Thanks in advance.

PD: The digital isolators are TI's ISO721C. I've tested individual bits toggling from the LPT port and I get the right behaviour on the isolated part of the interfase. The bus names in the upper left corner, are from LPT signals. It's like some kind of wiggler clone.

[ This message was edited by: matiasnabarro on 05-11-2007 20:31 ]

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Attachments :

jtag.JPG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HtIq&d=%2Fa%2F0X0000000aLK%2FhOdWEXsdo2431sCM_eZI350u87qWBzdpPV5wGDGHrkw&asPdf=false

m_tibu · ‎2007-11-16

Posted on November 16, 2007 at 10:14

Hi,

I've the same problem with a STR750 micro.

The HJTAG server doesn't respond to the auto detection command:

Unknown

0x00000000

I use a wiggler clone also on a STR912 board with HJTAG and it is working well. I was able to read the device ID, using not HJTAG, but OpenOCD for parallel port wiggler. Unfortunately this environment is not interfacing an RDI protocol that is ARM proprietary. (I have read this in a forum.)

So, it means that the str750 is doing well.

I'm tring to contact TWENTYONE who is the guy who have developed the hjtag server, but I had no success.

Which IDE are you using? (IAR, Realview, AXD, NoICE, Eclipse ...)

This is the link to the wiggler clone I have:

http://www.frozeneskimo.com/electronics/arm-tutorials/jtag-wiggler-clone/

Let's keep in touch to know if there is an HJTAG solution to the problem.

Marco