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pumpkin
Explorer
Explorer
8,065 Views
Registered: ‎06-22-2011

BER too high for PRBS-15

Hi all,

 

In IBERT, the BER for PRBS-7 is very low (E-13), and the link looks fine.

But when we test with PRBS-15, the BER is much higher (E-6).

What is wrong with the link?

 

Thanks

 

Xiang Chao

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2 Replies
gguasti
Xilinx Employee
Xilinx Employee
8,059 Views
Registered: ‎11-29-2007

PRBS-15 has an higher number of consecutive equal simbols. Your link has probably high ISI, this could be a long channel, maybe with many connectors... lot of distributed capacitance. Try to enable the DFE in order to compensate for ISI effect.

kind regards,

GG

 

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pumpkin
Explorer
Explorer
8,037 Views
Registered: ‎06-22-2011

Hi,

 

It IS a long link.

The DFE was enabled during the test. Should we tune the parameters of DFE?

According to your experience, is this link workable for a SATA3 device?

 

Thanks

 

Xiang Chao

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