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[FAQ] DS90UB949-Q1: single mode question

Part Number: DS90UB949-Q1

Dear team,

1. If the customer only uses single port, can they use port 1?

2. If the customer connect 949 to 948 and use dual link mode, is it ok to connect 949's port 0 to 948's port 1 and connect 949's port 1 to 948's port 0?

Thanks & Bets Regards,


  • Hi Sherry,

    1. Yes. You may configure single port and use PORT1 for 949 if you are paring with 948. There is a register 0x34[4:3] = 11 where you can set to PORT1 for single PORT1 secondary input.
    2. No. The 949 doesn't have port swap.


  • Hi Aaron,

    Thanks for your reply!

    For the item 1, Got it! 

    For the item 2, I am a little confused. If we use 949 single port 1, then it has to connect 948's port 0 because 948's I2C communication is only existing in the port 0. It has been swapped. Why dual port mode can't be swapped?

    Thanks & Best Regards,


  • Hi Sherry,

    I am not sure why we can't swap the port in dual link. Basically, the 949 doesn't have the swap port features where 948 can't be remotely swap the port. If you swap the inputs connection, the link is broken unless you have it physical change locally.