DS90UH949A-Q1: DS90UH949 -> fiber -> DS90UH948

Samir Alagic

Part Number: DS90UH949A-Q1

Hello,

I was wondering if it is possible to use optical fiber between DS90UH949 (serializer) and DS90UH948 (deserializer)?

My concern is regarding the back channel control data. Is it possible to disable the back channel i.e. letting the serializer act only as a transmitter and the deserializer only as a receiver?

Best Regards
Samir

over 5 years ago

0 Charley Cai over 5 years ago

TI__Genius 12866 points

Hi Samir,

This is possible. The serializer will only send forward channel data in this case. All we need to do it turn off back channel from the UB948.

Best Regards,

Charley Cai

0 Samir Alagic over 5 years ago in reply to Charley Cai

Prodigy 40 points

Hi Charley,

Great, thank you!

I have tried to find a "disable back channel function" in the UB948 datasheet without success. Also I keep ending up at the MODE_SEL1 strapping pin. i.e. there is no option without back channel disabled. Do you have any advice how I should proceed?

Best Regards
Samir

0 Charley Cai over 5 years ago in reply to Samir Alagic

TI__Genius 12866 points

Hi Samir,

Please try setting 948 register 0x63 bit 1 to 1.

Best Regards,

Charley Cai

0 Samir Alagic over 5 years ago in reply to Charley Cai

Prodigy 40 points

Hi Charley,

Great, thank you for the information.

Just for clarification, this means that it does not matter which value I select on the MODE_SEL1 strapping pin (back channel disbaled with 0x63 register)?

Best Regards

Samir

0 Charley Cai over 5 years ago in reply to Samir Alagic

TI__Genius 12866 points

Correct, however since you would need to power on the device and then configure the register.

There's some time where the back channel is still on before you enable the register.

Please ensure your system is not affected by that.

Best Regards,

Charley Cai

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DS90UH949A-Q1: DS90UH949 -> fiber -> DS90UH948