Universal USB Device Driver (USBIO)
Registry Entries
USB08 Evaluation Board Designer Reference Manual
MOTOROLA Universal USB Device Driver (USBIO) 239
E.9 Registry Entries
The behaviour of the driver can be customized by startup parameters
stored in the registry. The parameters are stored under a path that is
specified in the INF file. This registry path is
\HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\USBIO\Parameters
by default.
The location can be customized by changing the S_ConfigPath and
S_DeviceConfigPath1 variables in the [Strings] section of the
INF file.
The driver reads the parameters when a new device object is added. If
a parameter does not exist when the driver attempts to read it, the driver
creates the entry using an internal default value.
Table E-3 lists all registry parameters.
Table E-3. Registry Parameters Supported by the USBIO Driver
Value Min Default Max Description
RequestTimeout 0 1000 Time-out interval for synchronous I/O requests, in
milliseconds.
Zero means infinite (no time-out).
ShortTransferOk 0 1 1
If set to 1 short packets in read transfers are
allowed.
If set to 0 short packets in read transfers cause
errors.
UnconfigureOnClose 0 1 1 If set to 1 the device will be unconfigured when the
last file handle is closed.
If set to 0 the device state is not changed.
ResetDeviceOnClose 0 0 1 If set to 1 the device receives an USB reset if the
last file handle is closed.
If set to 0 the device state is not changed.
EnableRemoteWakeup 0 1 1 If set to 1 Remote Wakeup is enabled.
If set to 0 Remote Wakeup is disabled.
MaxIsoPackets 16 64 512 Maximum number of packets allowed is an
isochronous data transfer.
PowerStateOnOpen 0 0 3 Device power state that will be set when the device
is opened (first handle is opened).
0...3 correspond to D0...D3