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Chapter 3      Software Overview
NI-VXI User Manual
3-32
© National Instruments Corporation
  MapVXIAddressSize (size)
MapVXIAddressSize
 sets the size for mapping user windows. The
subsequent calls to 
MapVXIAddress
 will attempt to map a window of
the size passed to 
MapVXIAddressSize
MapVXIAddressSize
 only
provides a preferred size to the 
MapVXIAddress
. If it is not possible to
map a window to the given size, 
MapVXIAddress
 can use a different
size. To determine the exact size of window mapped, use the
GetWindowRange
 function.
Note:
Not all platforms support 
MapVXIAddressSize
.
  SetByteOrder (window, ordermode)
SetByteOrder
 sets the byte/word order of data transferred into or out
of the specified window. The two possible settings are Motorola (most
significant byte/word first) or Intel (least significant byte/word first).
The application must have Owner-Access Privilege to the applicable
window for this function to execute successfully. Notice that some
hardware platforms do not allow you to change the byte order of a
window, which is reflected in the return code of the call to
SetByteOrder
. Most Intel processor-based hardware platforms
support both byte order modes. Most Motorola processor-based
hardware platforms support only the Motorola byte order mode,
because the VXI/VMEbus is based on Motorola byte order.
  SetContext (window, context)
SetContext
 sets all of the hardware interface settings (context)
for a particular VXI/VME window. The application must have
Owner-Access Privilege to the applicable window for this function to
execute successfully. Any application can use 
GetContext
 along with
SetContext
 to save and restore the VXI/VME interface hardware
state (context) for a particular window. As a result, the application can
set the hardware context associated with a particular pointer into
VXI/VME address spaces (obtained from 
MapVXIAddress
). After
making a 
MapVXIAddress
 call for Owner Access to a particular
window (and possibly calls to 
SetPrivilege
 and 
SetByteOrder
),
you can call 
GetContext
 to save this context for later restoration by
SetContext
.