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AD9371 JESD PRBS

Question asked by am_ptt on Mar 5, 2018
Latest reply on Mar 20, 2018 by gverma

Hello,
I am working with AD9371 and JESD PRBS system: my target is validating the JESD link if possible both on the serializer level and on JESD framer.

 

In the ug992 I found references both for "PHY prbs testing" and for "transport layer\framer testing".

 

The first is referenced at
chapter "Serializer PRBS" ug992 pag 23
"The serializer has a built in PRBS test pattern it can output to aid in debugging the JESD204B serial link. If errors caused by signal integrity exist, it may be difficult to get the JESD204B framer/deframer to work properly. The PRBS generator built into the serializer allows the AD9371 to output serial data, even when the link may be causing bit errors. The PRBS generator can be configured to transmit PRBS7, PRBS15, or PRBS31 sequences. With this mode enabled, the serializer amplitude and emphasis can be adjusted to find the best setting to minimize bit errors on the serial link."

 

The second is referenced at
chapter "JESD204B INTERFACE\RECEIVERS (ADC) DATAPATH" ug992 pag 18
"Each framer is capable of generating a pseudorandom bit sequence (PRBS) on the enabled lanes. After the PRBS is enabled, errors can be injected. Enabling the PRBS generator disables the normal JESD204B framing, and may cause the SYNCB signal to deassert."

 

In the API the only reference for prbs testing is the function MYKONOS_enableRxFramerPrbs.

 

So it seems there are two prbs system but only one available through the API....

 

QUESTION:
1)
how many PRBS sources are available? 1 or 2?
which PRBS system is implemented (PHY or framer)?

 

2)
In the event there is a framer prbs where is it placed?
between the framer and 8b/10b encoder\decoder (8 bit datapath)
or before framer (16 bit datapath) ?
Could you provide detailed informartion about it.

 


Regards
AlessandroM

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