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Explorer
Explorer
798 Views
Registered: ‎01-18-2011

Independent control of QTR delays

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Hello

 

Can I increment NQTR delay independently, without incrementing PQTR delay?

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Community Manager
Community Manager
882 Views
Registered: ‎08-08-2007

Re: Independent control of QTR delays

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I doubled checked and they can be independently controlled. They’re two different registers with different controls, the delays are 512 taps so you could move them apart by as much as the delay line allows.

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4 Replies
Community Manager
Community Manager
747 Views
Registered: ‎08-08-2007

Re: Independent control of QTR delays

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Physically they are two separate lines with separate RIU registers so I think its possible though I’m not sure I understand the use case. Why do you want to move the P & N QTR delays away from each other?

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Explorer
Explorer
740 Views
Registered: ‎01-18-2011

Re: Independent control of QTR delays

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Data valid windows can be different. And clock edges can has different positions in the windows. So one QTR delay can stop during calibration, when the other QTR delay can continue to move.

 

PG150: "The data captured in the PQTR clock domain is transferred to the NQTR clock domain before being sent to the read FIFO and to the general interconnect clock domain. Due to this transfer of clock domains, the PQTR and NQTR clocks must be roughly 180° out of phase. This relationship between the PQTR/NQTR clock paths is set up as part of the BISC start-up routine, and thus calibration needs to maintain this relationship as part of the training (BISC_ALIGN_PQTR, BISC_ALIGN_NQTR, BISC_PQTR, BISC_NQTR)."

 

Thus, how far I can move apart P & N QTR delays from each other?

 

 

 

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Community Manager
Community Manager
883 Views
Registered: ‎08-08-2007

Re: Independent control of QTR delays

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I doubled checked and they can be independently controlled. They’re two different registers with different controls, the delays are 512 taps so you could move them apart by as much as the delay line allows.

-------------------------------------------------------------------------
Don’t forget to reply, kudo, and accept as solution.
-------------------------------------------------------------------------
Explorer
Explorer
686 Views
Registered: ‎01-18-2011

Re: Independent control of QTR delays

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Do I need to maintain any relationship between the PQTR/NQTR clock paths as pointed in PG150?

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