DS90UB913A-Q1: Bi-Directional Control in PCLK mode

Masaaki Sugiyama68

Expert 1445 points

Part Number: DS90UB913A-Q1

Dear Support Team;

Our customer uses PCLK mode.

But, Bi-Directional Control is unstable when PCLK inputs from imager.

The procedure is the following sequence.

(1)Initialize 913 and 914.

(2)Initialize imager

(3)Wait for PLL Lock of imager

(4)Bi-Directional Control from 914 to 913 (unstable)

PCLK input is stable form (3), but Bi-Directional Control is unstable.

Is there need to wait for PLL lock of 913 and 914 from PCLK input for Bi-Directional Control?

Best Regards,

Masaaki Sugiyama

over 8 years ago

0 Masaaki Sugiyama68 over 8 years ago

Expert 1445 points

Dear suport team;

Could you please give me some kind of answer?

Best Regards,

Masaaki Sugiyama

0 Liam Keese over 8 years ago in reply to Masaaki Sugiyama68

TI__Genius 12705 points

Hello,
For reliable communication of bidirectional control channel the serializer and deserializer should have lock status. After PLCK from imager is at final frequency recommend to apply digital reset1 (set reg 0x01[1] =1 to the 914A and then wait 22msec before resuming bidirectional control channel I2C commands.

0 Masaaki Sugiyama68 over 7 years ago in reply to Liam Keese

Expert 1445 points

Dear Liam-san;

Thank you for your reply.
I understood your mentioned sequence.

I have some additional questions.
- Does this sequence need in only PCLK mode?
- Could you tell me the reason of 22ms?
- Do I need this sequence when there are no PCLK in PCLK mode?
- Do I need this sequence after lock of PLL is loss?
- Are you updating Data Sheet for this sequence?

Best Regards,
Masaaki Sugiyama

0 Liam Keese over 7 years ago in reply to Masaaki Sugiyama68

TI__Genius 12705 points

Hello,
Please refer to section 9.1.2 in the DS90UB914A datasheet for most answers to your questions.

Regardless of mode you shoudl not attempt programming 914A I2C to remote seriializer or remote I2Cslave devices when Lock status is not valid otherwise no ACK will be returned over forward channel.
Deserializer data lock time for 914A is 22ms.

0 Masaaki Sugiyama68 over 7 years ago in reply to Liam Keese

Expert 1445 points

Dear Lian-san;

Thank you for your reply.

I referred to section 9.1.2 in the DS90UB914A datasheet.

- Is this sequence necessary for the External Oscillator Mode?

- How do we know that lock time (22ms) passed?　 Do we check the 0x1C[1](Signal Detect) ?

Best Regards,

Masaaki Sugiyama

0 Masaaki Sugiyama68 over 7 years ago in reply to Masaaki Sugiyama68

Expert 1445 points

Dear Lian-san;

Could you reply for these questions?

Our customer is waiting for these answers.

Best Regards,

Masaaki Sugiyama

0 Liam Keese over 7 years ago in reply to Masaaki Sugiyama68

TI__Genius 12705 points

Yes, similar sequence is needed with external oscillator when switching between internal SER clock and external oscillator.
You can monitor the lock pin, or poll the register for lock status on deserializer by I2C. Most customers implement a timer.

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DS90UB913A-Q1: Bi-Directional Control in PCLK mode