Signal transmission problem

Amy Luo

Hi TI team,

When serializer and deserializer transmit data through coaxial cable or STP, there will be forward and reverse data. My question is, are these two kinds of data transmitted in interval? Or superimposed together? For example, the deserializer sends an instruction to the serializer, and the serializer sends a string of data to the deserializer. This instruction and data are overlapped from the perspective of time axis? Or non overlapping? Now with the oscilloscope, it feels overlapping, but I can't understand how two digital signals, one high speed, one low speed, are superposed together, and how they are separated. Or is the oscilloscope too low?

Best Regards,
Amy Luo

over 6 years ago

0 Miguel Robertson over 6 years ago

TI__Guru 62920 points

Hi Amy.

Many serial communication protocols restrict transmission onto the bus to one node at a time. This is not always the case, though - for example, some deserializers feature a lower speed "back channel" for communication back to the serializer.

Is there a particular TI device your question concerns? If so it would help us to give a more specific answer.

Regards,

Max

0 Amy Luo over 6 years ago in reply to Miguel Robertson

TI__Expert 6895 points

Hi Max,

Thank you for your reply. The products used are ds90ub914 and ds90ub913.

Best Regards,
Amy Luo

0 Miguel Robertson over 6 years ago in reply to Amy Luo

TI__Guru 62920 points

Hi Amy,

Thanks for the info. I will mark this thread so that the team responsible for those products sees it.

Regards,
Max

0 Casey McCrea over 6 years ago in reply to Miguel Robertson

TI__Guru** 103215 points

Hello Amy,

These products use a TI proprietary signaling scheme which allows full duplex communication over the same conductor without time multiplexing. Each side of the link has both a transmitter and receiver, plus echo cancellation circuitry in order to recover the remote side signal while cancelling out the local driving signal. If you probe the line in the middle you will see a mixture of high speed and low speed data overlapping.

You can see more information about this protocol in our TIPL video here: https://training.ti.com/ti-precision-labs-what-is-fpd-link?context=1139747-1138099-1139854-1139837

Best Regards,

Casey

Interface

Interface forum

Signal transmission problem