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DS90UB964-Q1: Cable length

Kai Hsiao
Guru 12675 points
Part Number: DS90UB964-Q1

dear Sir 

When we connect 2m cable with 964 ,the screen will have blink ,but if we change to use 10m cable ,the screen will not have blink 

do you have any suggest about this issue ??

below is 2m and 10m register value 

Thanks 

964.rar

  • 0
    TI__Mastermind 30515 points

    Kai,

    sorry I can't open the attached. could you please help paste the plot here?

    regarding your issue, please help check:

    1. Please read AEQ registers 0xD2–0xD5 when working at 2m and 10m respectively;

    2. The 2m and 10m cable are from same vendor? which vendor? please past the S21/S12 parameters here. thanks.

    best regards,

    Steven

  • 0 in reply to Steven(Shenzhen) Shi
    Guru 12675 points

    dear Junqiang 

    1. Register compare as below 

    2. Register 0x22 / 0x37 / 0x4D / 0x4E / 0x56 / 0xDB is different ,but all of register are read only 

    3. Both of 2M and 10M cable AEQ register 

    0xD2 = 84 

    0xD3 = 27

    0xD4 = 60 

    0xD5 = F8

    1. do you have any idea about 2M cable screen blinking issue 

    2. 0xD5 bit 3:0 have description reg_35[5:4] ,but I can't find this register and don't understand what means Adaptive EQ floor value 

    3.0xD2 in our setting is 84 ,so bit2 is 1 ,May I know what's different between 1 and 0 ?? due to default value is 0

  • 0 in reply to Kai Hsiao
    TI__Mastermind 30515 points
    Hi,
    For the 2m cable application, please use default setting for AEQ. the AEQ_FLOOR is used for long cable application. So you don't need set the AEQ_FLOOR for 2m application.

    please see d/s description on AEQ's register for detailed message. thanks.

    2 SET_AEQ_FLOOR RW 0 AEQ adaptation starts from a pre-set floor
    value rather than from zero - good in long
    cable situations

    best regards,
    Steven
  • 0 in reply to Steven(Shenzhen) Shi
    Guru 12675 points

    Dear Junqiang 

    When I change 0xD2 register value from 0x84 to 0x80 

    The display output still have blink issue and there are more different register value between 2M cable and 10M cable 

    do you have any suggestion

    Different 

  • 0 in reply to Kai Hsiao
    Guru 12675 points

    Dear Sir 

    Below is S21/S12 parameters test result for 2M and 10M cable 

    Cable Vendor is Amphenol's Fakra cable 

    S21 for 2M

    S21 for 10M

    S11 for 2M

    S11 for 10M

  • 0 in reply to Kai Hsiao
    Guru 12675 points
    Dear Sir

    May I know you suggestion ?

    Thanks
  • 0 in reply to Kai Hsiao
    TI__Mastermind 30515 points
    Kai Xiao,
    Could you please help check the PCLK in this case?
    From the 2m and 10m cable comparison, the return loss of 10m cable is better. From your test result, it seems the register of 0xD3 is NOT correct when working at 2m cable, the value of register 0xD3 is 0x37, while for 10m cable, the 0xD3 = 0x27.
    so please check the power-on sequence firstly to secure UB964 can be adaptive the input data after power-on. besides, you can monitor the LOCK status, and cross-check by manually configuring the EQ value for UB964 under 2m cable test, to check whether it has flickering issue?

    regards,
    Steven