1956541_en-US

[#1]

JTAG connection for burning some Fuses on i.MX8M Nano UltraLite (BGA306)

Hello,

The „i.MX 8M Nano Hardware Developer’s Guide” has a new statement (compared to Mini) in Table 42 – Board bring-up checklist (item 5):

“i.MX 8M Nano cannot be connected to the JTAG controller while it is

running in the ROM code space. It can only be connected

to the JTAG controller when it has booted up successfully

from the external boot device.“

We use our own JTAG equipment to burn few Fuses (Boot mode, Key, JTAG Disable) on iMX8M Mini and Nano (also refer to https://community.nxp.com/t5/i-MX-Processors/Can-I-burn-eFuses-for-iMX8M-Mini-family-using-direct-re...).

At this stage there is no boot media on the adapter, but only the power supply and clock. The boot mode is Internal Boot (10b).

Now we would like to do the same JTAG-Fuse programming for the Nano UltraLite.

Would this be possible or is there a new restriction that was not present in the Mini/Nano?

Thanks.

Stefan

i.MX 8M | i.MX 8M Mini | i.MX 8M NanoRe: JTAG connection for burning some Fuses on i.MX8M Nano UltraLite (BGA306)

Hello @s_k 

After double check, the i.MX8MN should have the same behavior as the i.MX8MM according to the JTAG DAP after of reset.

Best regards,

Salas.

Re: JTAG connection for burning some Fuses on i.MX8M Nano UltraLite (BGA306)

Hello Alejandro_Salas,

Thanks for your reply.

I understood that the fuse map is the same.

But would the Nano UltraLite allow JTAG DAP access right after reset (JTAG_MOD = 0, no boot media), like the Mini?

Best regards,

Stefan

Re: JTAG connection for burning some Fuses on i.MX8M Nano UltraLite (BGA306)

Hello @s_k 

I hope you are doing very well.

As i.MX8MN has a "sub-family", all the i.MX8MN share the same fuse maps, so, there is not a restriction with i.MX8MN Ultra Lite.

Best regards,

Salas.