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K_ED_RD1's avatar
K_ED_RD1
Icon for New Contributor rankNew Contributor
1 day ago

Agilex 5 LVDS reciver with custom pins

Hi all, 

We are working on an Agilex 5  project based on Eagleboard with the device A5ED065BB32AE4SR0.

Our aim is to use the Cruvi connectors on the board, so we have to configure our pinning according to the board connections.  Therefore, we need to use custom pinning for our LVDS receivers.

We have been able to successfully set 4 LVDS lanes in I/O Bank 3B_B lane 1 and the reference clock in a differential pair of the same sub bank but in lane 2.

Then we tried to set a receiver with 8 lanes using the same 4 differential pairs from I/O Bank 3B_B lane1 and 4 available differential pairs from I/O Bank 3B_B lane2. Like in the following pin planner screenshoot

 The parameter editor looks like follows, no errors are shown on core generator

Once the LVDS receiver is regenerated and new pins assigned, we got the following error related to the 4 new lanes added:

Error(14566): The Fitter cannot place 4 periphery component(s) due to conflicts with existing constraints (4 I/O pad(s)). Fix the errors described in the submessages, and then rerun the Fitter. The Intel FPGA Knowledge Database may also contain articles with information on how to resolve this periphery placement failure. Review the errors and then visit the Knowledge Database at https://www.intel.com/content/www/us/en/support/programmable/kdb-filter.html and search for this specific error message number.

Error(175019): Illegal constraint of I/O pad to the location PIN_K65

Info(14596): Information about the failing component(s):

Info(175028): The I/O pad name(s): Sensor2_Data_n[4]

Error(16234): No legal location could be found out of 1 considered location(s). Reasons why each location could not be used are summarized below:

Error(20196): Location(s) already occupied and the components cannot be merged. (1 location affected)

Info(175029): PIN_K65. Already placed at this location: I/O pad Sensor2_Data_p[4](n)

Error(175019): Illegal constraint of I/O pad to the location PIN_K74

Info(14596): Information about the failing component(s):

Info(175028): The I/O pad name(s): Sensor2_Data_n[5]

Error(16234): No legal location could be found out of 1 considered location(s). Reasons why each location could not be used are summarized below:

Error(20196): Location(s) already occupied and the components cannot be merged. (1 location affected)

Info(175029): PIN_K74. Already placed at this location: I/O pad Sensor2_Data_p[5](n)

Error(175019): Illegal constraint of I/O pad to the location PIN_T74

Info(14596): Information about the failing component(s):

Info(175028): The I/O pad name(s): Sensor2_Data_n[6]

Error(16234): No legal location could be found out of 1 considered location(s). Reasons why each location could not be used are summarized below:

Error(20196): Location(s) already occupied and the components cannot be merged. (1 location affected)

Info(175029): PIN_T74. Already placed at this location: I/O pad Sensor2_Data_p[6](n)

Error(175019): Illegal constraint of I/O pad to the location PIN_T77

Info(14596): Information about the failing component(s):

Info(175028): The I/O pad name(s): Sensor2_Data_n[7]

Error(16234): No legal location could be found out of 1 considered location(s). Reasons why each location could not be used are summarized below:

Error(20196): Location(s) already occupied and the components cannot be merged. (1 location affected)

Info(175029): PIN_T77. Already placed at this location: I/O pad Sensor2_Data_p[7](n)

It seems like the fitter tries to create and assign new complementary ping where there are already assigned ones. 

Could you help us with this?

Best regards

Configuration
Generic Io
Programmable Logic Device

4 Replies

  • FvM's avatar
    FvM
    Icon for Super Contributor rankSuper Contributor
    7 hours ago

    Hi,

    inverted pins of differential pairs are assigned automatically by the fitter, you don't need to enter it in pin planner. Does the error also come up if you only assign p-pins?

    • K_ED_RD1's avatar
      K_ED_RD1
      Icon for New Contributor rankNew Contributor
      4 hours ago

      Hi,

      As you pointed, leaving the n-pins unassigned seem the fitter associate them automatically to their complementary ones. 

      However, we are allowed to direclty assingn the n-pins from lane 1 without any issue but not the ones belonging to lane 2 as the following image shows

      We would like to know what is the reason why one lane allows direct assign and the other no. Both lanes belong to the same HSIO bank. In the case shown in the image, would all LVDS lanes work properly?

      Thanks in advance

  • K_ED_RD1's avatar
    K_ED_RD1
    Icon for New Contributor rankNew Contributor
    11 hours ago

    Hi Aqid,

    Thanks for your response.

    The differential pair column looks fine as can be seen in the attached image

    This is the configuration for the LVDS pins in our QSF file:

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_p[0] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_p[1] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_p[2] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_p[3] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[0] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[1] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[2] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[3] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[4] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[5] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[6] -entity Lvds8lanes

    set_instance_assignment -name IO_STANDARD "1.2-V TRUE DIFFERENTIAL SIGNALING" -to Sensor2_Data_n[7] -entity Lvds8lanes

    set_location_assignment PIN_K77 -to Sensor2_Data_p[0]

    set_location_assignment PIN_M77 -to Sensor2_Data_n[0]

    set_location_assignment PIN_F77 -to Sensor2_Data_p[1]

    set_location_assignment PIN_H77 -to Sensor2_Data_n[1]

    set_location_assignment PIN_M67 -to Sensor2_Data_p[2]

    set_location_assignment PIN_K67 -to Sensor2_Data_n[2]

    set_location_assignment PIN_H67 -to Sensor2_Data_p[3]

    set_location_assignment PIN_F67 -to Sensor2_Data_n[3]

    set_location_assignment PIN_M65 -to Sensor2_Data_p[4]

    set_location_assignment PIN_K65 -to Sensor2_Data_n[4]

    set_location_assignment PIN_M74 -to Sensor2_Data_p[5]

    set_location_assignment PIN_K74 -to Sensor2_Data_n[5]

    set_location_assignment PIN_P74 -to Sensor2_Data_p[6]

    set_location_assignment PIN_T74 -to Sensor2_Data_n[6]

    set_location_assignment PIN_V77 -to Sensor2_Data_p[7]

    set_location_assignment PIN_T77 -to Sensor2_Data_n[7]

  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    Icon for Regular Contributor rankRegular Contributor
    14 hours ago

    Hi,

     

    In the Pin Planner, there is a column where you can see "Differential Pair".

    If it is not there, you need to add it manually by customizing the column.

     

    Please ensure every _p pin is matched with its correct _n companion pin.

     

    Regards,
    Aqid