USB HOST DRIVER V03 Freescale Semiconductor / Motorola, USB HOST DRIVER V03 Datasheet - Page 26

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

Each
(in Packets Data section), from the beginning of the buffer. The
determines the size of a packet buffer. The
result returned when the Driver completes the whole transfer.
An isochronous transfer may not be started immediately. The Client application can
specify the 11-bit
the transfer begins in this frame. Otherwise the
should be set in the
request in the queue and begins transmitting as soon as possible. This makes the Client
application capable of implementing a double buffering scheme. In this scheme the Client
should request a new transfer without waiting for the previous one to complete, by
specifying the
When the MOTUSB Driver completes I/O requests the
USB_ISO_XFER
ErrorCount
The
packet, or 0x9 if an error occurred (or short packet processed).
NOTE:
No more than 255 packets can be processed within a single isochronous transfer request.
3.4.1.
A write operation on isochronous–out endpoints performs isochronous data transfer from
the Host (PC) to the Device. To perform isochronous write transfers the Client
application should first establish connection to the pipe, build an isochronous transfer
buffer and specify it to
packets have to be less than or equal to the maximum packet size of the endpoint. There
must be no gaps between the data packets in the transfer buffer. The
member of the
transfer is started.
When the MOTUSB Driver completes write I/O requests, it changes the
of each packet according to the actual bytes which were processed in that packet.
Normally this field should be zero, indicating that all packet data was sent, otherwise this
field will contain the number of bytes remaining in the packet buffer as not sent.
3.4.2.
A read operation on isochronous–in endpoints performs an isochronous data transfer from
the Device to the Host (PC). In order to perform isochronous read transfers the Client
application should first establish a connection to the pipe, build an isochronous transfer
buffer and specify it to
M
Status
USB_ISO_PACKET
field of each
Isochronous Write Transfers.
Isochronous Read Transfers.
member of
USB_ISO_TRANSFER_ASAP
will specify the actual frame number when a transmission was started, the
USB_ISO_PACKET
StartFrame
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Flags
WriteFile
hold
ReadFile
USB_ISO_XFER
USB_ISO_PACKET
Offset
field of
number in the Fixed Header part of the buffer. In this case
Programming Interface.
(
structures have to be initialized correctly before the
(
ReadFileEx
WriteFileEx
member indicates the offset of the packet data buffer
USB_ISO_XFER
flag.
will specify the total error count in this transfer.
will be zero, for each successfully transmitted
Status
) Win32 API routines. The sizes of the
) Win32 API routines. The sizes of the
USB_ISO_TRANSFER_ASAP
. In such a case the Driver puts the
member indicates the I/O operation
StartFrame
Offset
Length
Length
and
member of
bit mask
member
member
Length
3-4