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TUSB8044AEVM: TUSB8044AEVM

Part Number: TUSB8044AEVM
Other Parts Discussed in Thread: TUSB8044A

Hello team

Could you help to get your advice on the below queries from my customer?

Target : TUSB8044AEVM

1. Design file for TUSB8044AEVM 

2. Way to set the USB2.0 RX, TX in UFP (SE0_NAK is occurring and cannot transit it to compliance mode)

3. Way to Set the parameters related RX/RX in USB2.0 & USB3.2 such as Pre-emphasis parameters, DC level ... and so on)

       this is because the TX Eye has not enough(attached) and need to adjust the filters

Please review and let me get your advice on those queries.

Thanks and Best Regards

Billy Yun

  • Hi Billy,

    1. Please accept my friend request so that I can send you the design files through E2E DM. Please post on your original thread once you have done so.

    2. Are you testing upstream or downstream hub ports of TUSB8044A? Downstream ports will need to be configured by connected PC using USB-IF compliance tool. 

    3. USB 2 eye attached looks good, why do you need to tune USB 2 TX? USB TX can be tuned via USB_R1 pull down resistor, see document linked below. USB 3 TX performance is fixed and cannot be adjusted.

       

  • Hi Malik

    Thanks and

    1. I have accepted on your friend request

    2. This is downstream. could you let me get the guidance on how to perform on the below with the details on USB-IF compliance tool?

       >>Downstream ports will need to be configured by connected PC using USB-IF compliance tool. 

    3. It seems that customer wants to optimize more on the eye and it should be cleared with the document.

    Please review and let me get your advice on 1 & 2.

    Thanks and Best Regards

    Billy Yun

  • Hi Billy,

    I have sent the design files to you. To place the TUSB8044A into it USB compliance mode  it must be connected to a Windows PC. The USB Host will enumerate TUSB8044A. Using the USB-IF test tool (xHSETT tool linked below, CRTL+F = xHSETT) you can place TUSB8044A into different compliance mode including SE0_NAK. You can also see this link () as a reference on what the SE0_NAK test is measuring. 

     

  • Hi Malik

    My customer has evaluated with the guidance of USB R1 but there's no significant improvement as below.

    And could you review and let me get your advice on the below queries?

    1. Is there any impact to Rx performance with adjusting the Drive strength or other USB2.0 Tx parameters?

    2. Is there any way to adjust of Tx Pre-emphasis?

    This is because there will be longer line and additional parasitic components in real PCB than EVM and need to have marginal performance.

    Please review and let me get your advice on this.

    Thanks

    Billy Yun

  • Hi Billy,

    1. Adjusting TX driver strength should not affect RX sensitivity performance. Increase drive strength may cause a slight increase in jitter but not significant.

    2. No USB 2 pre-emphasis. Customer will need to use USB 2 redriver to compensate for loss the leading edge of the USB 2 eye diagram in real application. TI USB 2 redriver compensate for loss in the leading edge of the eye diagram.