17.6.3.1 Enumeration Process
The USB protocol is a Host/Client protocol. This is the host that starts the enumeration sending requests to the device through the control endpoint. The device handles standard requests as defined in the USB Specification.
| Request | Definition |
|---|---|
| GET_DESCRIPTOR | Returns the current device configuration value. |
| SET_ADDRESS | Sets the device address for all future device access. |
| SET_CONFIGURATION | Sets the device configuration. |
| GET_CONFIGURATION | Returns the current device configuration value. |
| GET_STATUS | Returns status for the specified recipient. |
| SET_FEATURE | Set or Enable a specific feature. |
| CLEAR_FEATURE | Clear or Disable a specific feature. |
The device also handles some class requests defined in the CDC class.
| Request | Definition |
|---|---|
| SET_LINE_CODING | Configures DTE rate, stop bits, parity and number of character bits. |
| GET_LINE_CODING | Requests current DTE rate, stop bits, parity and number of character bits. |
| SET_CONTROL_LINE_STATE | RS-232 signal used to tell the DCE device the DTE device is now present. |
Unhandled requests are STALLed.