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SN65DPHY440SS: Is it okay to change positive signal and negative signal?

Part Number: SN65DPHY440SS

Dear TI experts,

My customer asked about changing positive signal and negative signal.

(i.e. applying positive input to DA0N, negative input to DA0P, positive input to DA1N, negative signal to DA1P, and so on.)

Is it okay to use this device like this and Is this fully operational?

Please check this issue. Thanks.

Best regards,


  • Chase

    The DPHY440 can't support polarity inversion, the above proposal will not work in DPHY440 default state. The high speed entry sequence consists of driving LP11->LP01->LP00 (LP->HS transition). If you flip the polarity, then the high speed entry sequence will be flipped as well and you will never able to enter into HS mode. 

    The only way it will work is that if the DPHY440 is in I2C mode and only HS mode is always enabled using the following sequence. The sequence puts the CLK and all data lanes into HS mode only.

    Write Register 0x50 with 8’h1F //Override enable for HS TX path

    Write Register 0x51 with 8’h1F //HS TX path enabled.

    Write Register 0x61 with 8’h00  // Disable LP path.

    Write Register 0x70 with 8’h1F  //Override enable for HS RX path

    Write Register 0x71 with 8’h1F  // HS RX path enabled.