We cannot get JTAG communication established with the 9261EK board. Perhaps once in 10 tries we get something meaningful back, but almost immediately afterward we lose connection. Our ETM/JTAG probe (Lauterbach LA7690) worked just fine with the RM9200EK. On the 9261EK, we set the probe to "926EJ".

We tried connecting the probe to both the ETM connector (J5) and to the JTAG connector (J7), same results. We checked for shorts between the JTAG pins on the board, all OK. We tried 10MHz and 32768Hz TCK frequency, no difference.

There are some differences between the 9261EK and 9200EK boards in the JTAG section. We changed jumpers so that the two are similar:
- Connect S2 (connect NTRST to processor)
- Disconnect S3, connect S6 (loopback TCK to RTCK)

This didn't help.

We also noted that resistor network RR1 is 100K instead of 10K as in the 9200EK board. We replaced it with a 10k resistor network. You guessed it: this didn't help as wel!!

Currently we're out of ideas, any suggestions are most welcome!

Thanks,

Mark Groninger.

I am using the Atmel SAM-ICE under the IAR toolchain with the AT91SAM9261-EK and it works well. This doesn't help you any with teh Lauterbach unit, but it sounds like you are unsure as to whether the EK JTAG works, and it does. The SAM-ICE is around $127 from DigiKey and the IAR 30 day eval is free.

Jonathan More

Thanks for responding!

Good to know the JTAG works. Since the probe works on other boards, it has to be a wrong setting somewhere. I am unfamiliar with the SAM-ICE and IAR tools. However perhaps the settings are similar to the Lauterbach system? I'd be much obliged if you'd be willing to share your settings, a screenshot would be great!

Thanks,

Mark.

"it has to be a wrong setting" - this is probably a little too hopeful. The whole JTAG debug process is complex and is driven by code and / or scripts that tell the JTAG probe the sequence needed to init the device and download the code. For example if you are trying to run code out of SDRAM, the SDRAM controller has to be initialized first via a sequence of JTAG commands usually via a script. So, try all the settings you can, but if it doesn't work call the vendor. Otherwise you have to debug their JTAG probe which is not at all pleasant.

We found that JTAG works if we pressed down on one side of the BGA. It could be a soldering quality issue, or a problem in the board. We replaced the board, the new board works fine!