Usbio_Iso_Transfer - Motorola USB08 Reference Manual

Universal USB Device Driver (USBIO)

USBIO_ISO_TRANSFER

Definition
Members
Designer Reference Manual
210
The USBIO_ISO_TRANSFER structure provides information used for
isochronous data transfers.
typedef struct _USBIO_ISO_TRANSFER{
ULONG NumberOfPackets;
ULONG Flags;
ULONG StartFrame;
ULONG ErrorCount;
} USBIO_ISO_TRANSFER;
NumberOfPackets
Specifies the number of packets to be sent to or received from the
device. Each packet corresponds to an USB frame. The maximum
number of packets in a read or write operation is limited by the registry
parameter MaxIsoPackets.
Flags
This field contains zero or any combination (bit-wise or) of the
following values.
USBIO_SHORT_TRANSFER_OK
If this flag is set, the USBIO driver does not return an error if a data
packet received from the device is shorter than the maximum
packet size of the endpoint. Otherwise, a short packet causes an
error condition.
USBIO_START_TRANSFER_ASAP
If this flag is set, the transfer will be started as soon as possible
and the StartFrame parameter is ignored. This flag has to be
used if a continuous data stream shall be sent to the isochronous
endpoint of the USB device.
StartFrame
Specifies the frame number the transfer shall start with. The value has
to be within a system-defined range relative to the current frame. The
range is normally set to 1024 frames.
If USBIO_START_TRANSFER_ASAP is specified in Flags, this
member has not to be set by the caller. It contains the frame number
that the transfer started with, when the request is returned by the
USBIO.
Universal USB Device Driver (USBIO)
USB08 Evaluation Board
MOTOROLA