C6678 I2C EEPROM Boot Issue

Daisuke Maeda

Guru 20205 points

There is TMS320C6678AXCYP25 (Encryption enabled) on our boards.

I2C Master mode boot fails.
I2C bus is not driven (SCL is held High).
Then DEVSTAT register is 0000140Ah which is Big Endian mode.

In I2C Master mode BOOTMODE[9] is Reserved bit.
When BOOTMODE[9] is '1' I2C bus is not driven.
When BOOTMODE[9] is '0' I2C bus is driven, but it fails.
Must GPIO[10] pin (BOOTMODE[9]) be pulled down?

Best regards,

Daisuke

over 12 years ago

0 Daisuke Maeda over 12 years ago

Guru 20205 points

I checked the RBL source codes below.

http://software-dl.ti.com/sdoemb/sdoemb_public_sw/rbl/1_0_C6678/index_FDS.html

In I2C Master mode BOOTMODE[9] is Reserved bit.
nyshI2cBootParamInit() refers to DEVSTAT[10] which is BOOTMODE[9].
If DEVSTAT[10] is not 0 the parameter for I2C Master mode is not selected.

nysh.c
nyshI2cBootParamInit() - line789

Therefore I guess that BOOTMODE[9] must be 0.

Best regards,

Daisuke

0 Bill Taboada over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 42545 points

Hi Daisuke,

I've forwarded your information to the engineers supporting the RBL. Once they've had a chance to review the issue I'll get back to you. Are you now booting with BOOTMODE[9]=0?

Regards, Bill

0 Daisuke Maeda over 12 years ago in reply to Bill Taboada

Guru 20205 points

Hi Bill,

Thank you for your reply.

Yes.

Booting with BOOTMODE[9]=0 succeeds now.

On our boards the GPIO[10] (BOOTMODE[9]) is pulled up.
Our boards have been manufactured.

If RBL has issue can I rewrite it?

Best regards,

Daisuke

0 Bill Taboada over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 42545 points

Unfortunately the ROM boot loader code cannot be rewritten. Unless we can find a different work-around you will have to pull GPIO[10] down.

Regards, Bill

0 Daisuke Maeda over 12 years ago in reply to Bill Taboada

Guru 20205 points

Hi Bill,

Thank you for your reply.

Is this issue fixed by the future silicon revision?

Best regards,

Daisuke

0 Bill Taboada over 12 years ago in reply to Daisuke Maeda

TI__Mastermind 42545 points

Hi Daisuke,

We need to complete our analysis to see if there is a work around. There are no future revisions of the silicon are planned so the more likely scenario would be an errata that adds the requirement that GPIO[10] be pulled low.

Regards, Bill

0 Daisuke Maeda over 12 years ago in reply to Bill Taboada

Guru 20205 points

Hi Bill,

Thank you for your reply.

I think also it must be inspected whether other reserved pins have the issues.

Best regards

Daisuke

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C6678 I2C EEPROM Boot Issue