USB HOST DRIVER V03 Freescale Semiconductor / Motorola, USB HOST DRIVER V03 Datasheet - Page 52

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

3.6.7.
Definition:
typedef struct _USB_ISO_PACKET {
} USB_ISO_PACKET, *PUSB_ISO_PACKET;
Members:
Offset
Packet buffer offset within isochronous transfer buffer pointed by USB_ISO_XFER
structure.
Length
Specifies packet length in bytes. The Client application should set this value for
isochronous transfers. When driver completes transfer I/O it fills this member with the
number of bytes actually processed for this packet. This value should be less than or
equal to endpoint packet size, defined in an endpoint descriptor of the pipe for which the
I/O operation should be performed.
Status
The driver returns packet transmitting result to this member. Zero means successful
transmission, 0x9 shows that a short packet was processed.
Comments:
This structure is used as part of an isochronous transfer request using the
structure and specifies the packet header information. The
offset from the beginning of the USB_ISO_XFER buffer.
To determine the isochronous transfer buffer size by a given Packet Count and Packet
Size use
will include header, packet headers and packet data buffers sizes
To get pointer to the isochronous packet data buffer by given transfer buffer and packet
index relative to the transfer buffer use the
M
ULONG Offset;
ULONG Length;
ULONG Status;
ISO_XFER_BUF_SIZE(PacketCount, PacketSize)
USB_ISO_PACKET
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Programming Interface.
PACKET_BUFFER(xfer, index)
Offset
macro. The result value
member contains the
USB_ISO_XFER
macro.
3-30