USB HOST DRIVER V03 Freescale Semiconductor / Motorola, USB HOST DRIVER V03 Datasheet - Page 14

• Manufacturer Part Number: USB HOST DRIVER V03
• Description: USB Host Driver v03
• Manufacturer: Freescale Semiconductor / Motorola

2.4. Device Object.
The USB Client Driver is loaded by the system components when connecting a USB
Device to a USB port. The PCI Enumerator component performs USB Driver selection,
according to the Drivers installed on the system, which loads and invokes the Driver
AddDevice dispatch table routine. As a result of this routine the MOTUSB Device Driver
itself creates a Device object and attaches this Device object to the USB Driver stack.
Each MOTUSB Device object is associated with a physical USB Device that is connected
to the USB. Due to this fact, MOTUSB can handle more than one Device connection.
State
Disconnected
Connected
Opened
Configured
Unconfigured
Locked
2.4.1.
When Device object creation occurs the Driver saves the Device and all configuration
descriptors. Following this the Driver performs SET_CONFIGURATION requests for
the configuration #0, and configures all the interfaces in that configuration.
M
Table 2.1 Device object states from Client point of view.
Default Device Configuration.
Description
No physical Device connection. Device object not created or destroyed.
All handles opened to Device became invalid and user mode Client is
responsible to close them.
Physical Device connection exists. Device object created.
configured (unconfigured) depending on the MOTUSB registry settings.
No invalid handles to Device became valid.
The handle to the Device object opened. Client application can perform Device
request on the Device.
Active configuration for Device selected. Client application can perform Device
request on the Device, open pipes and perform and interrupt transfers on those
pipes.
No active configuration for Device selected. Client application can perform only
limited set of requests. No pipe connections can exist.
Note: Application developers should not use this state. The purpose of this state
provided in MOTUSB is for USB test software only.
Lock access to Device for other owners with handle for the same Device.
Client application can lock access to the Device in two ways:
for 100% of working time, to monopolize access to the Device
lock on demand ensuring that some requests or data flow sequences will not be
interrupted by another USB Client application.
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Driver Model.
Device became
2-3