topic Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM in i.MX Processors

Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

rodrigo_travess — Fri, 16 Oct 2020 09:52:56 GMT

Hello,

At the AN4581 Application Note section 5.7 it is recommended to program the SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses to completely secure the device, but looking at both the IMX8MMRM and IMX8MMSRM, I wasn't able to find the exact location of those fuses (bank, word, bit). Where can I find this information?

Thank you!

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

igorpadykov — Sat, 17 Oct 2020 05:35:30 GMT

Hi rodrigo_travess

additional info were sent via mail.

Best regards
igor

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

stephanwächter — Thu, 15 Apr 2021 16:56:34 GMT

We also want to disable JTAG on the imx8m-mini and I couldn't find any info of about it in Reference Manual, Rev. 2, 08/2019 Chapter 6.2 Fusemap. Could you also point me into the right direction.

Thank you!

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

paul_geurts — Tue, 02 Nov 2021 13:26:54 GMT

Could you make this email public information? Why is this information not listed in the security reference manual? For the i.MX8M Nano this is listed in the security reference manual. But I cannot know whether the Mini uses the same fuses.

Also, AN4581 also lists fuse DIR_BT_DIS to be of interest. But I cannot find any reference of it.

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

jxb4256 — Tue, 19 Jul 2022 01:58:17 GMT

Can you also share this with me, please? Why isn't this just posted in a public app note, or the reference manual or security reference manual? Security through obscurity is not security.

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

johneubanks — Mon, 28 Aug 2023 21:46:11 GMT

@igorpadykov could you also send me the info for the JTAG_HEO fuse?
Thanks!

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

jbruno79 — Mon, 26 Feb 2024 12:17:49 GMT

hi @igorpadykov,

I need information about the fuses for the imx8m mini. Could you be so kind to provide it to me? I need to disable the JTAG for security reasons.

Best regrads,

Julián

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

tsmt — Thu, 13 Mar 2025 07:59:34 GMT

We also would like to have this information.

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

emmanuel_madrigal — Wed, 26 Mar 2025 16:38:00 GMT

Hi,

Would it be possible for you to send me this information as well?

Also is this diifferent between an imx8m nano and a mini?

Re: Programming SJC_DISABLE, JTAG_SMODE and JTAG_HEO fuses on iMX8MM

dj_RS — Thu, 17 Jul 2025 13:05:21 GMT

Hi @igorpadykov ,

I would appreciate if you could send me this information as well.

Thanks in advance