2.2.4.16 USB_DEVICE_Attach Function

C

void USB_DEVICE_Attach(
    USB_DEVICE_HANDLE usbDeviceHandle
);

Summary

This function will attach the device to the USB. It does this by enabling the pull up resistors on the D+ or D- lines. This function should be called after the USB device layer has generated the USB_DEVICE_EVENT_POWER_DETECTED event.

Precondition

Client handle should be valid. The device layer should have been initialized and an device layer event handler function should have been assigned.

Parameters

Returns

None.

Example

// This code example shows the set 
// of steps to follow before attaching the
// device on the bus. It is assumed that the
// device layer is already initialized.

USB_DEVICE_HANDLE usbDeviceHandle;

// Get an handle to the USB device layer.
usbDeviceHandle = USB_DEVICE_Open( USB_DEVICE_INDEX_0,
                                                  DRV_IO_INTENT_READWRITE );

if(USB_DEVICE_HANDLE_INVALID == usbDeviceHandle)
{
    // Failed to open handle.
    // Handle error.
}

// Register an event handler call back function with device layer
// so that we are ready to receive events when the device is 
// attached to the bus.

USB_DEVICE_EventHandlerSet(usbDeviceHandle, APP_USBDeviceEventHandler, NULL);

// Now, connect device to USB
USB_DEVICE_Attach(usbDeviceHandle);

Remarks

None.