AM2434: Managing reading and writing efuses on SoC

Matej Liska

Part Number: AM2434

Tool/software:

Hi all,
We are planning to read and write eFuse bits directly from the firmware in our applications using the AM2434 microcontroller.

We appreciate that eFuses are primarily utilized by the key writer for writing encryption and signing keys. However, our objective is to access a portion of the eFuse memory to check the state of our custom bits or to reburn them as needed.

Could you please clarify which specific parts of the eFuse memory in the AM2434 are safe to use from software for our purposes?
Additionally, we would like to understand the appropriate methods or functions available for reading from and writing to these bits, or documentation on this theme.

Thank you!

BR, Matej Liska.

3 days ago

+1 Prashant Shivhare 3 days ago

TI__Guru 69061 points

Hello,

Please refer to the following guides:

https://software-dl.ti.com/tisci/esd/latest/6_topic_user_guides/extended_otp.html

software-dl.ti.com/.../EXAMPLES_EXT_OTP.html

0 Matej Liska 2 days ago in reply to Prashant Shivhare

Prodigy 90 points

Hello Prashant, based on shared url and table

could we use AM2434 as AM64x device? Is there any information of hardware config of AM24x?

Thank you.

0 Prashant Shivhare 2 days ago in reply to Matej Liska

TI__Guru 69061 points

Matej Liska said:
could we use AM2434 as AM64x device

Yes, indeed. These are same devices from the security perspective. Any reference to AM64 in the SYSFW doc is applicable to AM243 as well.

0 Matej Liska 2 days ago in reply to Prashant Shivhare

Prodigy 90 points

Thank you Prashant, there is also information that describe access as: System Firmware allows for only one host in the system to have write access to the extended OTP region. This host is specified in the security board configuration Extended OTP array configuration using the write_host field.

Am i correct that we firstly need after each boot to set write_host ID (which could be any number), and then create several hosts? Is there any difference between hosts and permissions of R5 cores?

After set of host IDs, we could use them to read or write OTP rows?

BR, Matej Liska.