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DP149RSBEVM: regs default changing?

JongHa Lim
Prodigy 30 points
Part Number: DP149RSBEVM

Hi

I am using DP149 for retimer.

The problem is that DP149 has to connect to computer by usb to set some register for my system everytime.

So, Is there a way to change default register value so that It doesn't need to connect to computer?

thank you

  • 0
    TI__Mastermind 23815 points
    Hi JongHa,

    DP149 has a volatile memory, any change you make will be lost at power off.

    There is no way to make permanent changes to DP149 registers.

    Regards
  • 0
    TI__Guru 60870 points
    Also, the DP149 can be configured using pin configuration instead of register access if I2C_EN is pulled low. What configuration are you trying to set?
  • 0 in reply to JMMN
    Prodigy 30 points
    I usaully change registers below.
    0Ah[1:0] Retimer mode across full range 250 Mbps to 3.4-Gbps
    0Bh[4:3] TX termination 150 to 300-Ω
    0Ch[1:0] HDMI de-emphasis 2-dB
    0Ch[7:5] Data output swing in/decrease
    0Ch[4:2] Clock output swing in/decrease

    How can I set pin configuration for those settings..
    Thank you
  • 0 in reply to JongHa Lim
    TI__Mastermind 23815 points

    Hi JongHa,

    Retimer across the full range is only changed by I2C.

    Tx termination is only changed in by I2C.

    Pre-emphasis = -2dB is set by PRE_SEL=L

    Output swing depends on the resistor in Vsadj, review figure 18.

    By default in GPIO mode, DP149 changes functional mode between redriver and retimer at 1Gbps and Tx termination is selected automatically depending on the data rate, these default conditions are enough for DP149 to work properly.

    Regards