JTAG Test failed - the TDO/SWDIO pin held permanently high - session aborted-unable to connect to CPU

[muralidamodaran]

Hi,

I am using S32K144 IC.

Connected external crystal with - 12Mhz.

Initially the code is flashed, after changing clock registers one time only flashed.

After that I am getting the following error while flashing the code by IAR IDE with I-Jet debugger.

"session aborted-unable to connect to CPU"

When i am performing JTAG test with target board the attached error message is showing.

But I connected JTAG connections as per S32K144EVB-Q100 board J14 connector.

Please suggest what I have to do to solve this problem.

Thanks & Regards,

Murali P

[danielmartynek]

Hi,

Have you tried using the onboard OpenSDA programmer instead?

Did you reconfigured the JTAG pins in the flashed application?

Thanks,

Daniel

[muralidamodaran]

Hi,

Thank you for your ans.

1. I am not yet tried open SDA interface. I will check.

2. I think this is is the main problem

    because I observed actual problem later.

    If I configure JTAG pins as GPIO's in my code, First time/one time only I can flash the code in to CPU.

    next time it is shows the above error.

    But S32K144 datasheet showing JTAG pins also we can use GPIO's.

    Please suggest how to reconfigure JTAG pins in the flashed CPU.

Thanks & Regards,

Murali P.

[danielmartynek]

Hi Murali,

Please read this article:

https://mcuoneclipse.com/2013/06/16/bricking-and-recovering-frdm-kl25z-boards-reset-swd-clock-and-lo...

You can use the P&E Recovery Utility as shown there.

Thanks,

BR, Daniel

[muralidamodaran]

Hi,

Thanks for your quick response.

I followed different operation.

Since my CPU is flashed with code one time and I understood my CPU is running.

But not getting RESET when JTAG trying to reset or not responding for JTAG actions/signals (Observed with scope).

So I thought should stop the CPU clock to exit CPU form run mode,

For that I shorted CPU EXTAL pin to GND with jumper wire,before power ON.

Now I gave power to the board and connected JTAG. Loaded sample program.

Then it is flashed,  after that I removed ground connection from EXTAL pin.

Now I am able to flash the code into CPU normally.

Thanks & Regards,

Muirali P.