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TUSB7340: 4 USB2.0 cameras connected to TUSB7340 bandwidth?

Kevin Huang8
Genius 4475 points
Part Number: TUSB7340

Tool/software:

Hi Team,

If 4 USB2.0 cameras are connected to 4 x USB ports converted from TUSB7340 PCIe to USB bridge，

Will each USB2.0 have 480 Mbps? Or 4 USB2.0 devices equally share the 480 Mbps bandwidth?

  • 0
    TI__Guru*** 144895 points

    HI Kevin:

    USB Streaming of audio and video normally uses isochronous transfers – these are packet based periodic transfers that are initiated by the host which have fixed but guaranteed bandwidth. Host controllers guarantee this bandwidth by planning a schedule of transfers ahead of time to ensure there is enough time reserved on the bus.

      Normally USB2 bus  supports 384 Mbps of isochronous (80% of 480 Mbps) bandwidth,  4 USB2.0 devices equally share the 384Mbps bandwidth.. You may need to check what is  bandwidth for each camera used before using all 4 cameras.

    Regards

    Brian

  • 0 in reply to Brian Zhou
    Genius 4475 points

    Hi Brian,

    When two USB 3.0 Cameras + two USB 2.0 Cameras are connected to the 4 USB ports of the Bridge,
    The reference block diagram will be the bandwidth of two USB 3.0 Camera Share USB 3.0 HUB.
    And is the bandwidth of the two USB 2.0 Camera Share USB 2.0 HUB being correct?

  • 0 in reply to Kevin Huang8
    TI__Guru*** 144895 points

    Kevin:

    Kevin Huang8 said:
    bandwidth of two USB 3.0 Camera Share USB 3.0 HUB.
    And is the bandwidth of the two USB 2.0 Camera Share USB 2.0 HUB being correct

    this is correct.

    Best

    Brian