USB device status

When a USB device is plugged in to the host, the host uses a series of actions to enumerate the device configuration (the configuration is an enumeration state, which indicates the temporary State). These States are as follows:

1. Access state (attached): After a device is connected to a host, the host detects the access of the device by detecting the level changes on the signal line;

2. Power Supply Mode (powered): refers to the power supply to the device, which is divided into the default power supply value when the device is connected, and the power supply value after the configuration phase (by the maximum value required in the data, can be set through programming)

3. Default Mode: Before USB is configured, it communicates with the host through the default address 0;

4. Address: After configuration, after the USB device is reset, it can communicate with the host based on the unique address assigned to it by the host;

5. configured: uses various standard USB request commands to obtain various information about the device and modify or set the information about the device.

6. suspended state: If the USB Bus is idle, the device automatically enters the suspended state. After the device enters the suspended state, the total current power consumption cannot exceed 280ua.

connection	plus electricity	missing saved	editing address	Configuration set	hanging starting	description description
No	____	____	____	____	____	The device has not been connected to the interface. Other features are irrelevant.
Yes	No	____	____	____	____	The device has been connected to the interface but has not been powered on. Other features are irrelevant.
Yes	Yes	No	____	____	____	The device has been connected to the interface and powered on, but has not been reset.
Yes	Yes	Yes	No	____	____	The device is connected to the interface, powered on, and reset. No address has been assigned. The device is addressable at the default address.
Yes	Yes	Yes	Yes	NO / TD>	__	the device is connected to the interface and powered on. and reset. A unique address is assigned. not configured yet.
Yes	Yes	Yes	Yes	Yes	NO / TD>	the device is connected to the interface and powered on. and reset. A unique address is assigned and configured. the device function can be used.
Yes	Yes	____	____	____	Yes	The device cannot detect bus activity within at least 3 milliseconds and automatically enters the device if it is suspended. The device function is unavailable.

The preceding table lists the conversion relationships between the statuses of these external devices.

Device status Conversion Diagram