USBGetRemoteWakeupStatus Macro

#define USBGetRemoteWakeupStatus RemoteWakeup

This function indicates if remote wakeup has been enabled by the host. Devices that support remote wakeup should use this function to determine if it should send a remote wakeup. 

If a device does not support remote wakeup (the Remote wakeup bit, bit 5, of the bmAttributes field of the Configuration descriptor is set to 1), then it should not send a remote wakeup command to the PC and this function is not of any use to the device. If a device does support remote wakeup then it should use this function as described below. 

If this function returns FALSE and the device is suspended, it should not issue a remote wakeup (resume). 

If this function returns TRUE and the device is suspended, it should issue a remote wakeup (resume). 

A device can add remote wakeup support by having the _RWU symbol added in the configuration descriptor (located in the usb_descriptors.c file in the project). This done in the 8th byte of the configuration descriptor. For example: 

  ROM BYTE configDescriptor1[]={
    0x09,                           // Size 
    USB_DESCRIPTOR_CONFIGURATION,   // descriptor type 
    DESC_CONFIG_WORD(0x0022),       // Total length 
    1,                              // Number of interfaces 
    1,                              // Index value of this cfg 
    0,                              // Configuration string index 
    _DEFAULT | _SELF | _RWU,        // Attributes, see usb_device.h 
    50,                             // Max power consumption in 2X mA(100mA)
    
    //The rest of the configuration descriptor should follow

For more information about remote wakeup, see the following section of the USB v2.0 specification available at www.usb.org:

• Section 9.2.5.2
• Table 9-10
• Section 7.1.7.7
• Section 9.4.5

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