Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

How to turn on Cyclone V LVDS 100Ohm termination in Pin Planner?

Hi,

I am using Quartus-II v13.1 with the Cyclone V 5CSXFC6D6F31C8NES. I have several LVDS I/O pairs going to the LVDS interface of a high-speed ADC. One example of such an I/O pair would be pins AA26 (DIFFIO_RX_R21p) and AB27 (DIFFIO_RX_R21n). When I try to set "Tranceiver I/O Pin Termination" in the Pin Planner, I get the message, "This assignment is only for TX or RX pins". But these are RX pins, aren't they?

So, how do I enable 100Ohm internal termination for this LVDS pin pair?

Thanks!

9 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    --- Quote Start ---

    When I try to set "Tranceiver I/O Pin Termination" in the Pin Planner, I get the message, "This assignment is only for TX or RX pins".

    --- Quote End ---

    You'll select "differential" in column "input termination". You possibly need to enable the column. Transceiver termination is for GXB only.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    --- Quote Start ---

    You'll select "differential" in column "input termination". You possibly need to enable the column. Transceiver termination is for GXB only.

    --- Quote End ---

    Exactly the info I needed. Thanks! I had to enable the menu in order to select an input termination.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    According to Wndows standard, the pin list window has a context menu.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    right-click the pin table header and in "customuze columns..." add that column you want

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    Other than Pin Planner, you also can turn on the lvds 100 ohm termination from the assignment editor.

    From the assignment editor, you can select "Differential" for lvds input termination
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    You may enabled the 100 Ohm on chip termination for LVDS input through the QSF file directly. The following is an example of QSF assignment:

    set_instance_assignment -name INPUT_TERMINATION DIFFERENTIAL -to system_refclk
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    Hi,

    It is recommended for your to double verify if the 100Ohm termination has been enabled by run the Fitter compilation and then check the Fitter report. You may look for input pins section.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    This thread help me a lot. I must say I COMPLETELY forgot about the context menu where you enable and arrange the different columns. Would be nice to have an icon or something as a hint. (I too am using Quartus 13.1 so maybe this is different in newer versions. Also, in the 2015.05.04 version of the Quartus Settings File Reference Manual (MNL-Q21005) what's given for the syntax and example for INPUT_TERMINATION don't match!

    SYNTAX: set_instance_assignment -name INPUT_TERMINATION -to <to> -entity <entity name> <value>

    EXAMPLE: set_instance_assignment -name INPUT_TERMINATION "PARALLEL 50 OHM WITH CALIBRATION" -to pin_name

    Just an observation