MPC5744P cannot be connected to PE Multilink Universal FX anymore after last download

[Aili]

Hi,  I have been using PE Multilink Universal FX to download and debug firmware on MPC5744P for many times but today it suddenly stopped working. The MPC5744P is still operating normally per the last firmware download. However, I was not able to connect it to the PE emulator. The Information shown is as below: 

Warning: Device is not detected or may be censored. Please check connections or please enter password in GDB server parameters within debug configurations using the flag -uncensorpassword=n, then restart the debug session. 

I have checked JTAG signals and found TDI, TCK, and RESET signals were available (normal). RESET signal could also trigger the reset of MPC5744P. However, TDO signal was always stay low. 

Was it possible that the MCU was censored accidentally? I did not configure any censorship setting. 

Any help will be appreciated. 

Thanks,

Liping Zheng

[petervlna · Accepted solution]

Hello,

Was it possible that the MCU was censored accidentally? I did not configure any censorship setting.

Censoring device is not that simple. You will need at least to erase the Utest flash or program specific chapter of it with password and advance life cycle. But I do not know what you have done with micro.

Programmers has UTEST programing disabled by default.

Try to get the PEMicro SW programing tool from PE web if you can connect.

Or try different debugger vendor.

I have checked JTAG signals and found TDI, TCK, and RESET signals were available (normal). RESET signal could also trigger the reset of MPC5744P. However, TDO signal was always stay low

Even with debugger connected?

Best regards,

Peter

[Aili]

Hello Peter,

Thank you for your help!
Yes, with the debugger connected, I monitored the JTAG signals TDI, TCLK, TDO, RESET and TMS. When I click Debug buttom from S32 Design Studio, I saw digital signals for the lines TDI, TCLK, TMS and RESET. However, TDO was always stayed low.
What I just found out is that the JCOMP pin which has a 10 kohm pull down resistor is shorted to ground (possibly at MCU internal). Could this be the root cause?
Best Regards,
Liping

[petervlna]

Hello,

Thank you for details.

It looks like you have issue with debugger or its cable.

Because JCOM is input, Internally pulled down, the could be also external pull down to strengthen it.

In this state is JTAG in reset and you cant do anything with it. JCOMP is pulled up by debugger.

Best regards,

Peter

[Aili]

Hi Peter,

I found JCOM PIN of the MPC5744P was shorted to ground (without JTAG connected). Was it due to ESD?

Thanks,
Liping

[petervlna]

Hello,

Yes, that would be due to EMC.

As you don't want floating input to micro if there is no external pull-down.

Best regards,

Peter

[Aili]

Hi Peter, 

Thank you again for your help. Yes, we also think ESD was the possible cause of MCU input pin damage although we do have a 10kohm pull-down resistor onboard. 

Best regards,

Liping