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TUSB2E11: How to strap the TUSB2E111YCGR to use it in basic repeater mode

reza anvari
Prodigy 50 points
Part Number: TUSB2E11


Tool/software:

I want to use the TUSB2E111YCGR as a very basic "eUSB2<=>USB2" level converter (no I2C or GPIO needed, no charger) without any configuration over I2C bus.

Table 5-4 on the datasheet doesn't provide such an option and I am wondering how to hook up the SDA/SCL to have it as a repeater right  after the power up.

Thank you!

Reza

  • 0
    TI__Mastermind 27925 points

    Hi Reza,

    eUSB2 isn't simply 3.3V to 1.2V level-shifted USB 2.0.  The eUSB2 signaling will change based on whether it's connected to an eUSB2 host or peripheral.

    If you want a level shifter, you can utilize UART mode to disable the eUSB2 to USB 2.0 conversion and turn it into a level-shifter.

    What is the application?

    What is embedded USB2.0 (eUSB2)? | Video | TI.com

    Top Four Things to Know About eUSB2 (ti.com) (Section 2)

    Regards,

    Nicholaus

  • 0 in reply to Nicholaus_Malone
    Prodigy 50 points

    Hi Nicholaus, 

    I have a high end SoC which has eUSB2 interface and I need to connect it to a different MCU on the same board which has the legacy USB2 on it.

    To make this to work I need the eUSB2 Repeater as shown below,

    SoC (eUSB2) eD-/eD+ (eUSB2 HOST) <=> eUSB2 Repeater <=> MCU (USB2.0) D-/D+ (USB2.0 Device) 

    I need to know how to strap the TUSB2E111 to use it as mentioned above.

    Regards,

    Reza

  • 0 in reply to reza anvari
    TI__Mastermind 27925 points

    Hi Reza,

    I see.  In non-I2C mode, the options are shown in Table 5-2 as you mentioned, and Figure 11-2 shows typical application.  SDA should be pulled low and SCL should be pulled low with 160ohms or less.

    Since the repeater will be configured as a host, charger detection does not apply.  It is N/A, so GPIO0 and GPIO1 do not need to be routed to SoC.

    GPIO0 and GPIO1 are used to configure the USB PHY signal conditioning settings as described in Table 5-3 on power-up.  There is a note (1) in the pin descriptions for GPIO0/GPIO1; when they are configured as in input, but not actively driven, there should be a 1Mohm pulldown on GPIO0 and GPIO1 if they will not be pulled high.  However, you may want to change these to tune your USB PHY based on the eye-diagram results during USB 2.0 compliance.

    Regards,

    Nicholaus

  • +1 in reply to Nicholaus_Malone
    Prodigy 50 points

    Hi Nicholaus,

    Thank you for the clarification! I will follow the TBL 5-4 1st row which shows "Non-I2C USB Repeater Mode", SCL with 160 Ohm pull down and SDA with 0 Ohm to GND. Also I will keep some place holders for the potential PHY tuning needs.

    Regards, Reza  

  • 0 in reply to reza anvari
    Prodigy 50 points

    Hi Nicholaus,

    One more thing, your initial suggestion was to use the "Non I2C UART" mode (CEA-936-A, pure level shifter) but then you suggested the "Non I2C USB repeater" mode. 

    Non I2C UART mode >> SCL=PULL-up, SDA=PULL-down

    Non I2C USB repeater mode >> SCL= [0-160] Ohm SDA=GND

    Could you elaborate a bit more here?

    Regards, Reza

  • 0 in reply to reza anvari
    TI__Mastermind 27925 points

    Hi Reza,

    Correct. It was a misunderstanding on my part.  When you used the term "level converter", I mentioned that the UART mode on the TUSB2E11 can be used as a kind of level-shifter.  After clarifying the application, it's clear you don't need it and that you just need to use non-I2C USB repeater mode. 

    Regards,

    Nicholaus

  • +1 in reply to Nicholaus_Malone
    Prodigy 50 points

    Hi Nicholaus,

    Great and thank you for all the help.

    Regards, Reza