Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK Data Sheet
Product codes
AT91SAM9M10-G45-EK
808
SAM9M10 [DATASHEET]
6355F–ATARM–12-Mar-13
38.5.12
Power Modes
38.5.12.1
Controlling Device States
A USB device has several possible states. Refer to Chapter 9 (USB Device Framework) of the Universal Serial Bus
Specification, Rev 2.0.
Specification, Rev 2.0.
Figure 38-19.
UDPHS Device State Diagram
Movement from one state to another depends on the USB bus state or on standard requests sent through control
transactions via the default endpoint (endpoint 0).
transactions via the default endpoint (endpoint 0).
After a period of bus inactivity, the USB device enters Suspend Mode. Accepting Suspend/Resume requests from
the USB host is mandatory. Constraints in Suspend Mode are very strict for bus-powered applications; devices
may not consume more than 500 μA on the USB bus.
the USB host is mandatory. Constraints in Suspend Mode are very strict for bus-powered applications; devices
may not consume more than 500 μA on the USB bus.
While in Suspend Mode, the host may wake up a device by sending a resume signal (bus activity) or a USB device
may send a wake-up request to the host, e.g., waking up a PC by moving a USB mouse.
may send a wake-up request to the host, e.g., waking up a PC by moving a USB mouse.
The wake-up feature is not mandatory for all devices and must be negotiated with the host.
Attached
Suspended
Suspended
Suspended
Suspended
Hub Reset
or
Deconfigured
Hub
Configured
Bus Inactive
Bus Activity
Bus Inactive
Bus Activity
Bus Inactive
Bus Activity
Bus Inactive
Bus Activity
Reset
Reset
Address
Assigned
Device
Deconfigured
Device
Configured
Powered
Default
Address
Configured
Power
Interruption