T1024 SERDES in unidirectional mode

[gauravverma]

Hello, 

I want  to interface two T1024 chips using SERDES in unidirection mode. Is it possible to achieve it by only connecting Tx line of one chip to Rx link of other chip. What settings has to be incorporated in firmware to enable unidirection feature.

[ufedor]

From the hardware point of view it is possible to connect two processors using PCIe interfaces after configuring one as RC and another as EP.

Though such configuration is possible, it is not supported in the Linux SDK and there is no single document describing it.

[gauravverma]

What will happen ... If serdes is used in sgmii mode?      

Want to clarify again.... Only One tx (rx unconnected) of a chip is connected to rx (tx unconnected)of other chip ...

[ufedor]

> Only One tx (rx unconnected) of a chip is connected to rx (tx unconnected)of other chip ...

This configuration will not work.

[gauravverma]

What I am understanding is ...receiver pll should be synchronized before using serdes..

If I manipulate serdes of first chip's(tx connected and rx unconnected) receiver by connecting rx to tx of second serdes (same chip) ...Will this configuration work??

[ufedor]

This configuration will not work.

[gauravverma]

Thanks Udedor for your help...

As per your reply ... Serdes's both lines (TX and RX) have to be connected for chip - chip communication between T1024 processors. So unidirectional communication is not possible by connecting only tx of a chip to rx of other chip...

 Can you suggest me a way for unidirectional communication between two T1024 chips such that no reverse path exists (in hardware)...

Thanks & Regards

Gaurav

[ufedor]

Neither of high-speed serial interfaces can be used unidirectionally.

It is possible to use UART.

[gauravverma]

Thanks UFEDOR.....

last opinion from you....

I went  through following presentation .... 

http://www.nxp.com/assets/documents/data/en/supporting-information/WBNR_FTF10_NET_F0568.pdf 

Can we use RGMII interface for unidirectional communication ?

Which factor makes serial high speed serial communication unsuitable for unidirectional communication?

Thanks

Gaurav

[ufedor]

There is no hardware limitation to use RGMII unidirectionally.