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Method for testing a USB port and the device for the same

  • US 6,701,401 B1
  • Filed: 11/07/2000
  • Issued: 03/02/2004
  • Est. Priority Date: 07/14/2000
  • Status: Active Grant
First Claim
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1. A method for testing a USB port, which comprises the steps of:

  • reading in an I/O base address of a USB host controller;

    initializing a parallel port;

    testing whether the GND signal is disconnected by setting the D1 and D2 pins of the parallel at high voltages and measuring the D3 pin of the parallel port;

    testing whether the VCC signal is disconnected by setting the D1 and D2 pins of the parallel at low voltages and measuring the D0 pin of the parallel port;

    testing whether the D+ and D−

    form a short circuit with GND by setting the D1 and D2 pins of the parallel port at high voltages and reading the statuses of the D+ and D−

    from the USB host controller;

    testing whether D+ and D−

    form a short circuit with VCC by setting the D1 and D2 pins of the parallel port at low voltages and reading the statuses of the D+ and D−

    from the USB host controller;

    testing whether D+ and D−

    are disconnected by setting the D1 and D2 pins of the parallel port at low voltages and then at high voltages and reading the statuses of the D+ and D−

    from the USB host controller;

    testing whether D+ and D−

    form a short circuit by setting the D1 and D2 pins of the parallel port first at high voltages and then at low voltages and reading the statuses of the D+ and D−

    from the USB host controller; and

    displaying the test result.

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