National Instruments NI-VXI - Manual (Page 87)

Chapter 3 Software Overview
© National Instruments Corporation 3-49 NI-VXI User Manual
frame (for an embedded CPU) or the first extended controller (in an
external CPU situation).
EnableVXItoSignalInt (controller, levels)
EnableVXItoSignalInt is used to sensitize the application to
specified interrupt levels being processed as VXI signals. After calling
InitVXIlibrary , the application can sensitize itself to interrupt
levels for which it is configured to handle. RouteVXIint specifies
whether interrupts are to be handled as VXI/VME interrupts or as VXI
signals (the default is VXI signals). An
EnableVXItoSignalInt
call enables interrupt levels that are routed to VXI signals. Use
DisableVXItoSignalInt to disable these VXI interrupts. Use
EnableVXIint to enable interrupts not routed to VXI signals. A -1
(negative one) or local logical address in the controller parameter
specifies the local embedded controller or the first extended controller
(in an external controller situation). If a
RouteVXIint call has
specified to route a particular VXI/VME interrupt level to the VXI
signal processing routine and the global signal queue becomes full,
DisableVXItoSignalInt is automatically called to inhibit these
VXI interrupts from being received from the appropriate levels.
EnableVXItoSignalInt is automatically called to enable VXI/VME
interrupt reception when SignalDeq is called.
GetVXIintHandler (level)
GetVXIintHandler returns the address of the current VXI/VME
interrupt handler routine for the specified interrupt level. If interrupts
are enabled (via
EnableVXIint ), the callback handler for a specific
logical address is called. You must first call RouteVXIint to route
VXI/VME interrupts to the callback handler (as opposed to the signal
processing routine). A default handler,
DefaultVXIintHandler , is
automatically installed for every applicable VXI interrupt level when
the
InitVXIlibrary function is called.
RouteVXIint (controller, Sroute)
RouteVXIint specifies whether status/ID values returned from a
VXI/VME interrupt acknowledge cycle are routed to a VXI/VME
interrupt handler or to the VXI signal processing routine. The function
RouteVXIint specifies whether the status/ID value should be handled
as a signal or handled locally by a VXI/VME interrupt handler. Two
methods are available to handle VXI signals. Signals can be handled
either by signal handlers (as signals) or by queueing on a global signal