Hello,
I am considering disabling JTAG in i.MX8MPlus.
I have written to 0x470[21] and 0x470[23:22] (No debug mode) as described in the following forum.
https://community.nxp.com/t5/i-MX-Processors/How-to-disable-JTAG-on-i-MX-8M/m-p/966421
The command that I used is as follows.
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u-boot=> fuse prog -y 1 3 0xe00000
Programming bank 1 word 0x00000003 to 0x00e00000...
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Reading it after that will give out the results below.
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u-boot=> fuse read 1 3
Reading bank 1:
Word 0x00000003: 88e00000
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0x88000000 is the value already there from default.
I then tried connecting JTAG to see if JTAG was disabled, but JTAG is still enabled.
Are there any other Fuse bits that need to be written besides 0x470[21] and 0x470[23:22] to disable JTAG?
Best regards
Only this:
Thank you for the reminder.
I am currently in the process of investigating whether JTAG can be disabled.
I have already written to the Fuse bit you mentioned.
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u-boot=> fuse read 1 3
Reading bank 1:
Word 0x00000003: 88e00000
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I then connected JTAG to check the operation.
However, JTAG still able to read the ID codes of devices connected to the JTAG chain.
I think this means JTAG is not disabled.
Is my understanding correct?
Thank you in advance for your response.