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Chapter 3 Software Overview
© National Instruments Corporation 3-31 NI-VXI User Manual
GetVXIbusStatusInd (controller, field, status)
GetVXIbusStatusInd
retrieves information about the current state of
the VXI/VMEbus.
The information that can be returned includes the state of the Sysfail,
ACfail, VXI interrupt, TTL trigger, or ECL trigger lines as well as the
number of VXI signals on the global signal queue. The specified
information returns in a single integer value. The field parameter
specifies the particular VXI/VMEbus information to be returned. An
individual hardware platform might not support the specified hardware
signals polled. In this case, a value of -1 is returned in status. Interrupt
service routines can automatically handle all of the conditions retrieved
from this function, if enabled to do so. You can use this function for
simple polled operations.
GetWindowRange (window, windowbase, windowend)
GetWindowRange
retrieves the range of addresses that a particular
VXI/VMEbus window can currently access within a particular
VXI/VMEbus address space. The windowbase and windowend output
parameters are based on VXI/VME addresses (not local CPU
addresses). The window parameter value should be the value returned
from a
MapVXIAddress
call. The VXI/VME address space being
accessed is inherent in the window parameter.
MapVXIAddress (accessparms, address, timo, window, ret)
MapVXIAddress
sets up a window into one of the VXI/VME address
spaces and returns a pointer to a local address that will access the
specified VXI/VME address. The accessparms parameter specifies
Owner Privilege/Access-Only Privilege, the VXI/VME address space,
the VXI/VME access privilege, and the byte ordering. The value of the
timo parameter gives the time (in milliseconds) that the process
will wait checking for window availability. The function returns
immediately if the window is already available, or if the timo value
is 0. The timo field is ignored in a uniprocess (nonmultitasking)
system. The return value in window gives a unique window identifier
that various calls such as
GetWindowRange
or
GetContext
use to get
window settings. When a request for Owner Privilege is granted, you
can also use this window identifier with calls such as
SetContext
or
SetPrivilege
to change the hardware context for that window.