Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

 941

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13



Set TXPKTRDY and read it back until actually read at 1.



Clear TXPKTRDY so that no packet is ready to be sent.



.)

A USB device has several possible states. Refer to Chapter 9 of the Universal Serial Bus Specification, Rev 2.0.

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).

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.

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. 

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