DS90UB927Q-Q1: BIST Related Questions

Kenichiro

Part Number: DS90UB927Q-Q1
Other Parts Discussed in Thread: DS90UB928Q-Q1

[ DS90UB927-Q1 & DS90UB928-Q1 ] BIST Related Questions

Hi,

Can you help me to address few BIST related queries from my customer?
See the drawing below.

<Q1: BIST Enable/Disable through resistor>:

According to the datasheet, the BIST mode can be controlled through BISTEN pin or BIST control register of deserializer.
However, we still have similar resistor in serielizer, this case DS90UB927-Q1.

Can this resistor of DS90UB927-Q1 do the same function with DS90UB928=q1's?

<Q2 I2C communiaction during BIST>:

Is it possible to use I2C communication for local devices (HOST - UB927) and between remote devices (HOST - UB928 via UB927)?
If this can work, the BIST can be controlled from HOST sitting on serializer through I2C remote access.

Thank you for your support in advance.
Regards,
Ken

over 7 years ago

0 Palaniappan Manickam over 7 years ago

TI__Genius 10475 points

Hello,
The BIST mode is typically configured from the deserializer side either using the BISTEN pin or through the BIST control register.

0 Kenichiro over 7 years ago in reply to Palaniappan Manickam

Mastermind 9165 points

Palaniappan,

I know that from datasheet.
Can you please take a look into my questions?

<Q1: BIST Enable/Disable through resistor>:

According to the datasheet, the BIST mode can be controlled through BISTEN pin or BIST control register of deserializer.
However, we still have similar resistor in serielizer, this case DS90UB927-Q1.

Can this resistor of DS90UB927-Q1 do the same function with DS90UB928=q1's?

<Q2 I2C communiaction during BIST>:

Is it possible to use I2C communication for local devices (HOST - UB927) and between remote devices (HOST - UB928 via UB927)?
If this can work, the BIST can be controlled from HOST sitting on serializer through I2C remote access.

0 Kenichiro over 7 years ago in reply to Kenichiro

Mastermind 9165 points

Hi Palaniappan,

Can you please support this one?

Thanks,
Ken

0 Kenichiro over 7 years ago in reply to Kenichiro

Mastermind 9165 points

Hi Palaniappan or other friends,

Can you support this post? This issue has been tracked at major OEM through my customer (tier-1).

Without having confirmation, this cannot be closed.

Thanks,

Ken

0 Palaniappan Manickam over 7 years ago in reply to Kenichiro

TI__Genius 10475 points

Ken,
No, the BIST mode needs to be enabled from the deserializer side.

0 Kenichiro over 7 years ago in reply to Palaniappan Manickam

Mastermind 9165 points

Thanks, Palaniappan,

Can you or somebody in your team support Q2 below?

---
<Q1: BIST Enable/Disable through resistor>:

According to the datasheet, the BIST mode can be controlled through BISTEN pin or BIST control register of deserializer.
However, we still have similar resistor in serielizer, this case DS90UB927-Q1.

Can this resistor of DS90UB927-Q1 do the same function with DS90UB928=q1's?

Ken,
No, the BIST mode needs to be enabled from the deserializer side.

Okay, I understand that 0x14[0] of DS90UB927 is unnecessary information. I will send feedback to remove it.

<Q2 I2C communication during BIST>:

Is it possible to use I2C communication for local devices (HOST - UB927) and between remote devices (HOST - UB928 via UB927)?
If this can work, the BIST can be controlled from HOST sitting on serializer through I2C remote access.

---

Thanks,
Ken

0 Palaniappan Manickam over 7 years ago in reply to Kenichiro

TI__Genius 10475 points

For Q2, the BIST has to be enabled locally at the deserializer side and this can be either through I2C write or BISTEN.

See this related E2E thread on the same question:
e2e.ti.com/.../605801

0 Kenichiro over 7 years ago in reply to Palaniappan Manickam

Mastermind 9165 points

Thank you for sharing good reference, Palaniappan.

Please arrow me to double check.

> Writing deserializer register remotely from serializer will not work.

(Quote from reference post)

Does this mean, during BIST mode, the I2C communication for both direction (forward and back) cannot be used?
Correct?

<Reference Post>:

DS90UB928Q-Q1: disable BIST mode by I2C through BCC
e2e.ti.com/.../605801