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Altera_Forum's avatar
Altera_Forum
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11 years ago

Cyclone V LVDS_RX IP

Hi all,

I am working with Cyclone V to implement lvds_rx.

There is a different option about LVDS_Rx IP of cylone V devices compared with others series:"Is this interface constrained to the left, or right banks?".

User guide says that This option determines the PLL compensation mode in Cyclone V devices. But It doesn't have detailed information about the difference between the PLL compensation in left or right banks and others banks, and i can't to evaluate the performance of this interface.

I am looking forward your reply.

Thanks.

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    There is a fundamental difference in Cyclone V, as compared to previous families, to increase the performance of the LVDS interfaces. Whereas previously (e.g. in Cyclone IV) and LVDS I/O pin pair could be specified as input of output, Cyclone V has dedicated LVDS input and output pins.

    So, there will be limitations as to where LVDS RX pairs can be placed. This may also affect which PLLs can be used for compensation.

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    i can't to evaluate the performance of this interface

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    How are you expecting to evaluate it? Are you hoping to take real measurements off a hardware platform?

    Put your design together, constrain it and let Quartus tell whether it's good to go or not. Then relocate your LVDS rx pairs to the other side of the device (so, presumably, it uses a different PLL) and get Quartus to tell you whether it meets your constraints.

    Regards,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Hi,a_x_h_75,

    Thank you very much.

    I am planning to use two HMCs in up and bottom banks,so the LVDS interfaces must be placed in the right bank.

    Dose the LVD interfaces in right banks has the better performance or the performance depends on the specific designs?

    Best regards.
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Sorry it's been a while...:)

    There isn't (necessarily) any performance benefit using the right bank as compared to any other. Put your design together and see if it works at the speed you need.

    Cheers,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    --- Quote Start ---

    Sorry it's been a while...:)

    There isn't (necessarily) any performance benefit using the right bank as compared to any other. Put your design together and see if it works at the speed you need.

    Cheers,

    Alex

    --- Quote End ---

    Thank you very much!