AM335x based device: device ID

Alyautdin Roman

Other Parts Discussed in Thread: AM3359

Hi!

Our product is based on AM335x SoC and we want to hardcode some ID data for
each device. Different methods are considered but we prefer to have
some kind of on-Soc persistent storage for ID.

What opportunities does Am335x give?

It has ROM for initial bootloader, is there a method to use memory inside? Access it from
A8 or M3?
Also there are custom efuses. Is it possible to use them during our manufacturing?

Also theoretically there could be persistent storage for PRU binary or M3 binary as
we would prefer not to have access to this storage from uboot.

Any ideas,
Roman

over 9 years ago

0 Brad Griffis over 9 years ago

TI__Guru*** 125430 points

Can you use the MAC address as an ID? Is it a requirement that you define the ID or are you just looking for some kind of unique identification? There is not any user programmable non-volatile storage in AM335x.

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

Hi Brad,

You are right we are looking for unique identification.
So this "custom efuse" wont help us, am I right?

Also an i2c EEPROM is mentioned in AM335x TRM (p4122) as data storage of layout for external NAND memory that is used by ROM code, is it considered to be external chip or this is AM335x internal eeprom?

Thanks,
Roman

0 Brad Griffis over 9 years ago in reply to Alyautdin Roman

TI__Guru*** 125430 points

Alyautdin Roman said:
So this "custom efuse" wont help us, am I right?

I don't see the term "custom efuse" anywhere in the TRM or DM. What are you referring to?

Alyautdin Roman said:
Also an i2c EEPROM is mentioned in AM335x TRM (p4122) as data storage of layout for external NAND memory that is used by ROM code, is it considered to be external chip or this is AM335x internal eeprom?

External.

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

According to TI Employee answer here:
Quote: "Yes, these are effuse registers. In some of them there are R/W bits (CEFUSE). These are customer effuses."
Also please refer to p1153 table 8-25 of TRM.
So the question is if this R/W registers could be used for our product identification

0 Brad Griffis over 9 years ago in reply to Alyautdin Roman

TI__Guru*** 125430 points

There are certain scenarios where TI does custom devices where customers can define the values of certain e-fuses. These are high volume engagements and involve NREs, license agreements, special order terms, etc. Even in that very rare scenario, those fuses *still* need to be blown by TI at the factory. As I have already stated, there is not any user programmable non-volatile storage in AM335x.

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

Thanks for support!

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

We will try to workaround this

0 Brad Griffis over 9 years ago in reply to Alyautdin Roman

TI__Guru*** 125430 points

So will the MAC address not work? You get 3 MAC addresses per device, and those are guaranteed to be unique.

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

Could they be calculated from Chip Part Number or they are taken from TI internal pool randomly generated?

0 Brad Griffis over 9 years ago in reply to Alyautdin Roman

TI__Guru*** 125430 points

They're taken from the TI pool, yes. They're sequential, not random.

0 Alyautdin Roman over 9 years ago in reply to Brad Griffis

Intellectual 345 points

Having AM3359 and knowing its MACs am I able to calculate/quess/see somewhere those MACs for the chip of the Devie if I am able to read information on chip package

0 Brad Griffis over 9 years ago in reply to Alyautdin Roman

TI__Guru*** 125430 points

It can only be read from the register.

Processors

Processors forum

AM335x based device: device ID