TMS570LS0914: Unable to access the DAP

Those are my registers from IcePack

Those are my registers from Dap

Hi Bernat,

Please try to do the steps given in the below thread:
(+) Error connecting to the target - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

You may have to 'retry' a bunch of times like 10's or more times while pressing the 'reset' (not Power on Reset) button.

--

Thanks & regards,
Jagadish.

Hi Jagadish,

Thanks for the answer but we can't make it work the reset + connect. 

We click in system reset and then to connect button for arm, but after several tries nothing happens.

Hi again, 

After reviewing it more we noticed that, as it can be seen in one of my previous images, the DEVICE_ID is set to 0, which is wrong.

So one possibility is that the error we have is the Invalid Device Id, mentioned here -> Debugging JTAG (ti.com) which is consistent with the original error received of Cannot acces the DAP Debugging JTAG (ti.com) But we haven't find out how to fix it in that case

Hi Bernat,

Are you using a TI launchpad or a custom board? Are there any pull resistors on those signals? If the signal trace is very long for example >10inches, any termination is added to the reduce the reflection? 

Is a custom board, but this problem never appeared until we used the self test functions that left our board in this state.

About JTAG signals, following signals have indeed a pull down resistor. 
 
nTRST - pull down resistor
TCK - pull down resistor

And, just to be sure, referring to the previous commented process for unlocking this situation. 

The "reset button" that needs to be pushed while we are trying to connect (once we have already connected the icepick and the DAP) is the /RST input port signal pushed to low (pin 81). Is that right ?