DS90UB914A-Q1: Constraints on maintaining back channel communication

Tomoaki Yoshida

Expert 2200 points

Part Number: DS90UB914A-Q1
Other Parts Discussed in Thread: DS90UB913A-Q1

Hi,

My customer is considering a system using DS90UB913A-Q1 and DS90UB914A-Q1.

The circuit is designed and software design is done.

They are designing along the application notes at the URL below.

http://www.tij.co.jp/jp/lit/an/snla222/snla222.pdf

They have vague concern about back channel communication.

Is there any constraint that communication will be interrupted once the register is set and back channel communication is established?

For example, if the interruption time is several microseconds after communication starts, communication is canceled.

over 8 years ago

0 Palaniappan Manickam over 8 years ago

TI__Genius 10475 points

Hello, your question has been received and assigned for Apps to look at.

0 Tomoaki Yoshida over 8 years ago in reply to Palaniappan Manickam

Expert 2200 points

Hi,

Any update on this issue?
I am waiting for updates of information.

Best regards,
Tomoaki Yoshida

0 Liam Keese over 8 years ago in reply to Tomoaki Yoshida

TI__Genius 12705 points

Hello,
when exercising backchannel communication and I2C it is important to ensure that a stable lock condition exists. After initial configuration, typically the camera will be set to proper PCLK frequency which will cause a momentary re-lock of the 913A-914A. During this time any attemped I2C transactions over backchannel may be interrupted , so I2C to remote slaves should be gated by Lock pin = High. After PCLK set to final frequency issue digital reset to 914A for consistent initialization as outlined in datasheet.

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DS90UB914A-Q1: Constraints on maintaining back channel communication