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TUSB1044: TUSB1044RNQ display alt mode functionality || Mux requirement

Part Number: TUSB1044
Other Parts Discussed in Thread: TUSB1146, TUSB1064

Tool/software:

Hi 

We are using re-driver partTUSB1044RNQ part in our project for Type-C interface and we need display ALT mode functionality also in the design. We are using Intel SoC in the design and this SoC is not having in-built MUX for display functionality.  So now doubt is, TUSB1044RNQ is having in-built mux or not for display switching functionality or we will have to use external MUX for it. 

1. Will TUSB1044RNQ work as only re-driver and will not provide in-built MUX functionality? Please confirm.

2. In the datasheet, it is mentioned display alt mode but in the block diagram of TUSB1044RNQ, MUX is not shown, so it is confusing. 

Please confirm these queries.

  • Hi,

    The TUSB1044 does not have a MUX on the high speed lines. If you need the re-driver + MUX, consider using the TUSB1146 (for a DP source) or the TUSB1064 (for a DP sink).

    1. Will TUSB1044RNQ work as only re-driver and will not provide in-built MUX functionality? Please confirm.

    Yes, it is only a re-driver for the four high-speed data lanes. There is a MUX for the AUX/SBU lanes only.

    2. In the datasheet, it is mentioned display alt mode but in the block diagram of TUSB1044RNQ, MUX is not shown, so it is confusing. 

    The part supports DP alt mode re-driving and AUX/SBU MUXing, but there is no MUX on the USB/DP lanes. This part is intended to be used with a processor that has a built-in USB/DP MUX.

    Let me know if you have any questions.

    Best,

    Shane

  • Thanks Shane for your reply.

    We are facing one issue that Type-C port is working on single side only as there is some issue in SW configuration regarding flip orientation. If want to use this re-driver without any software configuration, can we use it by Hardware control. I mean without any software dependency, can this re-driver be used for both orientation of Type-C ports?

  • Hi,

    You can configure the 1044 in GPIO mode if you do not want to use I2C to control the device. To do this, pull down the I2C_EN pin:

    GPIO mode lets you use the 1044 by using pullup/pulldown resistors on the pins to configure the device.

    Can you show a block diagram of how the 1044 is connected to the USB and DP lines in your system? I'd like to make sure you have the signal routing correct as you might need an external MUX.

    Best,

    Shane

  • Hi Shane,

    Please share your email ID. I will share type-C section schematic on your mail.

  • Hi,

    Its our group's policy to handle support through E2E exclusively. To share a schematic privately, please accept my friendship request and direct message the PDF file on E2E.

    Best,

    Shane

  • Hi Shane...  I have attached schematic file for review. 

    and also let us know the changes in schematic to use re-driver without software control. 

  • Hi,

    The only issue I see in the schematic is that you have two 100K pullups on AUXn and two 100K pulldowns on AUXp. You should remove one set of these resistors.

    I do not see the connection from the 1044 to your USB host. Make sure there is a MUX for USB/DP if this is not integrated in your host.

    To change the TUSB1044 from I2C to GPIO mode:

    1. Change the pullup on I2C_EN to a pulldown:

    2. Route FLIP, CTL0, and CTL1 to your PD controller's GPIO pins. The GPIO pins need to be configured for orientation control (FLIP), USB3 enable (CTL0), and DisplayPort enable (CTL1).

    3. Pull SLP_S0# high with 4.7Kohms if you do not want to control this with the PD controller.

    Best,

    Shane

  • Hi Shane,

    2. Route FLIP, CTL0, and CTL1 to your PD controller's GPIO pins. The GPIO pins need to be configured for orientation control (FLIP), USB3 enable (CTL0), and DisplayPort enable (CTL1).

    Can we make pull up/pull-down combination for these pins (FLIP, CTL0, and CTL1) also instead of routing to GPIO of PD controller? I mean using HW control for these pins instead of software control?

  • Hi,

    You can choose to pull up/down CTL0 and CTL1 if you want the 1044 to operate in only one specific mode:

    CTL0/CTL1 = 1/1: 2 lane USB3 + 2 lane DisplayPort

    CTL0/CTL1 = 1/0: USB3 only (no DisplayPort)

    CTL0/CTL1 = 0/1: 4 lane DisplayPort (no USB3)

    I don't recommend doing this because it limits the 1044 to one mode of operation. If you are ok with this then you can pull these pins high or low.

    You cannot pull the FLIP pin up or down because FLIP is based on the orientation of the Type-C cable. This needs to connect to your PD controller so the 1044 knows which direction the USB-C cable is in.

    Best,

    Shane