Questions of HID OVER I2C Enumeration RRS feed

  • 问题

  • I am Currently developing a hid-over-i2c device.

    I want to know What the OS(Windows8.1) will do after Retrieving Report Descriptors.

    In one case, by capturing the waveform I find the OS will send Set_Power_ON Command after Retrieving Report Descriptors.

    But in another case, I find the OS execute "Read" operation after Retrieving Report Descriptors.
    Why the OS would execute "Read" operation without asserting the GpioInt?
    And when the OS executes "Read", the SCL line will PullDown due to no data for reading.

    Best regards

    Best regards

    1. Retrieve ACPI ASL code for HID I2C DEVICE from System BIOS.
    2. Retrieve HID Descriptor from the Device.
      • Write HID Descriptor Address
      • Read HID Descriptor
    3. Issue a SET_POWER to the Device.
      • Write SET_POWER Command
    4. Issue a RESET (Host Initiated Reset) to the Device.
      • Write RESET Command
      • Device asserts GPIO interrupt
      • Read value (0x00 0x00) from input register
    5. Retrieve report descriptor from the device.
      • Write report descriptor address
      • Read report descriptor

    2013年12月31日 6:52