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AD9371 Lane Assignment - Rx/Tx/ORx

Question asked by spraju87 on Nov 14, 2016
Latest reply on May 23, 2018 by AdrianC

Hello,

I see that the AD9371 has 4 dedicated lanes for Rx/ORx and 4 for Tx. Based on the user guide, it seems to be possible that as long as the lane rate is less than 6144 Mbps, we could reduce the number of lanes for Rx/ORx and Tx depending on the IQ rate. Since we are using an FPGA with only 4 GTx transceivers, I'm planning for the following assignment :

 

Rx/ORx : 2 lanes (IQ rate of 122.88 MHz, dual channel enabled for Rx => lane rate of ~ 4900 Mbps)

Tx : 2 lanes (IQ rate of 150 MHz, dual channel enabled for Tx => lane rate of ~ 6000 Mbps) 

 

So, my questions are :

 

1) Is this lane assignment a good approach ? are there any recommendations ?

 

2) If I assign only 2 lanes for Rx/ORx combined, is it possible for me to change the assignment of lanes to Rx/ORx dynamically during run time ? i.e. I want to do the following depending on the user settings :

 

(a) Both lanes used for dual channel Rx (4 converters) at 122 MHz IQ rate.

(b) Both lanes used for dual channel Rx (4 converters) at 122 MHz IQ rate, use the remaining bandwidth for ORx at reduced rate i.e. both Rx channels and ORx converters data are sent over the shared lanes. 

(c) Both lanes used for dual channel Rx (4 converters) at reduced IQ rate, use the remaining bandwidth for ORx at high data rate i.e. both Rx channels and ORx converters data are sent over the shared lanes. 

(d) One lane dedicated to Rx(2 converters) at 122 MHz IQ rate and One lane dedicated to ORx.

(e) One lane dedicated to Rx(4 converters) at reduced IQ rate and One lane dedicated to ORx.

 

I want to know if all of these assignments for Rx/ORx are supported or not esp. (b) and (c) ?

Also, please do let me know if the lane assignment in general between Rx/ORx can be dynamically switched ? i.e can I switch from (a) to (d) or (e) during run-time ?

 

Thanks,

Raju

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