SPC56XX JTAG Password Send Sequence

[tbnkr]

I have a SPC56XX part which I need to unlock for a JTAG OnCE debug session.The procedure for enabling debug on a locked device is described in AN4035, however when I follow the steps I get no response from the MCU when sending correct password. Is there a more detailed explanation of the procedure for sending JTAG password to the MCU?

Thanks

[Erwan YVIN · Accepted solution]

Hello ,

"While the device is being held in system reset state shift the 64-bit password into the CENSOR_CTRL register (via the JTAG port using the JTAG ENABLE_CENSOR_CTRL instruction. The JTAG serial password is compared against the serial boot flash password from the flash shadow block."

Do you use TRACE32 JTAG (Lautechbach) or PpcMicro (Nexus)

You should configure your password into the settings.

the default password is 0xFEEDFACE CAFEBEEF

have you tried with PLS UDE STK ?

Best regards

Erwan

[tbnkr]

Hi and thank you for the quick response.

I have a Multilink programmer which successfully unlocks the MCU on boot. For my application I need to have some JTAG/Nexus functionality, which I implement myself, that's why I am trying to better understand the process of unlocking the device. I am using app note AN4035, but some things are a bit unclear at the moment.

My understanding of the steps required for unlocking the MCU are:

• Assert Reset and shift out 64-bit password in the CENSOR_CTRL register (somewhere I read that the actual register is 65 bits wide - is that correct?)
• De-assert Reset and try to enter OnCE status register in order to confirm the device is unlocked

Can you confirm if I am on the right path here?