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Linux/OPT8241: About data output problems?

Part Number: OPT8241
Other Parts Discussed in Thread: OPT9221,

Tool/software: Linux

Hi Ti Employee:

  • When I enable the phy_test mode ,output data is 0,0,1,2,3,...255...;But when I normally test, the output data is wrong. I think OPT9221 is working properly, OPT8241 does not work properly, causing LVDS to output wrong data; or there is a problem with DDR, resulting in the data after DDR processing is not correct. Is it possible to check if DDR is working properly or OPT8241 is normal Working related register?
  • There are many OPT8241 registers we do not have, can provide us with some of the OPT8241 and OPT9221 can verify the normal communication of some registers,In the absence of light, why the output amplitude and ambient are 0, the reasons for this problem in addition to saturation, there are other reasons?
  • VD_IN related instructions, I would like to know VD_IN only in the slave mode to configure it? Does this pin need control in Master mode?
  • After testing the VD_FR, VD_QD, VD_SF, HD_QD and VSYNC, LVDS output waveform speed slows down with the increase of time, what is the reason, and after the soft reset can not be restored, is not that the OPT8241 is not working properly?
  • Feedback signal on the entire data acquisition impact? Is it possible to collect some data without lighting and modulation? Can it be light sensitive?

Thanks.

Best Regards!

Looking forward to your reply!

-Kevin

  • When I enable the phy_test mode ,output data is 0,0,1,2,3,...255...;But when I normally test, the output data is wrong. I think OPT9221 is working properly, OPT8241 does not work properly, causing LVDS to output wrong data; or there is a problem with DDR, resulting in the data after DDR processing is not correct. Is it possible to check if DDR is working properly or OPT8241 is normal Working related register?

    >> Kevin: I think I answered this one before. If you violate VCO frequency limit (between 300MHz to 600MHz), the OPT8241 internal PLL may not work properly leading to clocking issue. Please make sure when you configure the clock tree (mod_mx, mod_nx, etc) VCO frequency range is observed.

    There are many OPT8241 registers we do not have, can provide us with some of the OPT8241 and OPT9221 can verify the normal communication of some registers,In the absence of light, why the output amplitude and ambient are 0, the reasons for this problem in addition to saturation, there are other reasons?

    >> OPT8241 registers are write-through OPT9221 registers. These are the TG registers in OPT9221 data sheet. You can also probe LVDS between OPT8241 and OPT9221 that outputs A+B, and A-B what do you see?

    VD_IN related instructions, I would like to know VD_IN only in the slave mode to configure it? Does this pin need control in Master mode?
    >> VD_IN is useful only in slave mode, where ToF chipset operates as a snapshot camera. In streaming mode VD_IN is not used and should be NC.

    After testing the VD_FR, VD_QD, VD_SF, HD_QD and VSYNC, LVDS output waveform speed slows down with the increase of time, what is the reason, and after the soft reset can not be restored, is not that the OPT8241 is not working properly?
    >> This sounds like PLL not locking onto a fixed frequency. Again, check your clock tree configuration. If that's not the issue, you may have a broken OPT8241.

    Feedback signal on the entire data acquisition impact? Is it possible to collect some data without lighting and modulation? Can it be light sensitive?
    >> Illumination feedback path can should be turned off. Disable both 'delay_fb_corr_mode' and 'delay_fb_dc_corr_mode'. You can collect data by introduce ambient light, just don't shine directly into the sensor.
  • Hi,Larry:

        Thank you for you reply!

        How to disable both 'delay_fb_corr_mode' and 'delay_fb_dc_corr_mode?

    Is this register configured?

  • If 'delay_fb_dc_corr_mode' andn 'delay_fb_corr_mode' are set to 0 (default), they are disabled.