SJC_DISABLE blocking flashing over SWD

[dafela]

Hi,

When blowing the SJC_FUSE on an i.MX RT1060 two things seems to happen:

1. The debug session I have open over SWD with an MCU-Link connected seems to stop working immediately
2. I'm unable to start new debug sessions or perform other actions towards the MCU using the MCU-LINK and SWD

While this is OK, I'm wondering if disabling the JTAG interface on the MCU also disables any SWD interactions?

Thanks,
Daniel

[Gavin_Jia · Accepted solution]

Hi @dafela ,

Please kindly refer to this pic：

Gavin_Jia_0-1733471598614.png

SJC_DISABLE negates both lines, so both are blocked. Either JTAG/SWD or even test control.

Bests,
Gavin

[dafela]

Hi @Gavin_Jia,

Thanks for confirming!
Out of curiosity, where is this picture from?

Kind regards,
Daniel

[Gavin_Jia]

Hi @dafela ,

It is from AN12419: Secure JTAG for i.MXRT10xx.

ANs related to security features now require an NDA and a permission request to access them.

Best regards,
Gavin

[dafela]

Thanks!