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usbd

setup

Set up a URB for an isochronous transfer

Synopsis:

#include <sys/usbdi.h>

int usbd_setup_isochronous( struct usbd_urb *urb,

_uint32 ﬂags,

_int32 frame,

void *addr,

_uint32 len );

Arguments:

urb An opaque handle (from usbd

alloc

urb()).

ﬂags One of the following:

•

URB_DIR_IN—specify incoming (device-to-PC) transfer.

•

URB_DIR_OUT—specify outgoing (PC-to-device) transfer.

•

URB_DIR_NONE—don’t specify the direction.

You can optionally OR in either or both of the following:

•

URB_ISOCH_ASAP—allow transfer as soon as possible (overrides

frame).

•

URB_SHORT_XFER_OK—allow short transfers.

frame The device frame number. This is ignored if

URB_ISOCH_ASAP is set.

addr The address for the start of the transfer. You must use the buffer allocated

by usbd

alloc().

len The length (in bytes) of the data transfer.

Library:

libusbdi

Description:

This routine sets up a URB for an isochronous transfer.

Returns:

EOK Success.

Classiﬁcation:

QNX Neutrino, QNX 4

76 Chapter 4 • USB Library Reference September 10, 2007

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Belkin F8E211 Guida Utente Pagina 90