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SMS's avatar
SMS
Icon for New Contributor rankNew Contributor
6 years ago

Soft LVDS IP core bitslip

I am using Max10 and included Soft LVDS IP core for data transmission and reception. For link training I sent 8'h0F. Now, the data at LVDS Rx slips every clock cycle.

I have tried to align it using the rx_data_align but that does not resolve the issue. LVDS IP was configured as:

General:

Power Supply Mode: Single Supply (for 10M16SAE144I7G)

Functional Mode: Rx

No. of channels: 1

SERDES factor: 8

PLL Settings:

Use external PLL (checked)

Receiver Settings:

Enable bitslip mode (checked)

Bitslip rollover value: 1

I have also tried to use internal PLL in which case the the bitslip occurs at random intervals. Now how can I fix this issue?

3 Replies

  • IDeyn's avatar
    IDeyn
    Icon for Contributor rankContributor

    Hi SMS,

    It is a strange behaviour - in case align is stable you shouldn't get bitslip as it is on first figure.

    You could attach your project in order for community to check it.

    --

    Best regards,

    Ivan

  • SMS's avatar
    SMS
    Icon for New Contributor rankNew Contributor

    Attached are two projects one for Tx and one for Rx. I am programming the DE10-Lite board (10MDAF484C7G) as Tx and a custom board (10M16SAE144I7G) as Rx.

    • IDeyn's avatar
      IDeyn
      Icon for Contributor rankContributor

      Hi SMS,

      I quickly checked your project and I can say that you should begin with a creation of constraint file (sdc).

      You should start with create_clock command, FE create_clock -name {I_ADC_FCO} -period 20.000 -waveform { 0.000 10.000 } [get_ports {I_ADC_FCO}]

      After that and after successful timing analysis you should test if your design works.

      --

      Best regards,

      Ivan