National Instruments NI-VXI - Manual (Page 88)

Chapter 3 Software Overview
NI-VXI User Manual 3-50 © National Instruments Corporation
queue. The RouteSignal function specifies which types of signals
should be handled by signal handlers, and which should be queued on
the global signal queue for each VXI logical address. If the VXI/VME
interrupt status/IDs are specified to be handled by a VXI/VME
interrupt handler, the level and status/ID value is sent to the appropriate
callback handler when an interrupt occurs. An individual handler
can be installed for each of the seven VXI/VME interrupt levels.
EnableVXIint and EnableVXItoSignalInt must be used to
sensitize the local CPU to interrupts generated by VXI/VME interrupts.
Only the levels routed to the appropriate handlers (VXI/VME
interrupts or VXI signals) via the
RouteVXIint function are enabled.
SetVXIintHandler (levels, func)
SetVXIintHandler replaces the current callback handler for the
specified VXI/VME interrupt levels with an alternate callback handler.
If VXI/VME interrupts are enabled (via
EnableVXIint ), the
VXI/VME interrupt handler for a specific logical address is called.
The
RouteVXIint function must first be called to route VXI/VME
interrupts to the callback handler (as opposed to the signal processing
routine). A default handler,
DefaultVXIintHandler is automatically
installed when the InitVXIlibrary function is called for every
applicable VXI/VME interrupt level. You can use
SetVXIintHandler to install a new callback handler.
VXIintAcknowledgeMode (controller, modes)
VXIintAcknowledgeMode specifies whether to handle the VXI/VME
interrupt acknowledge cycle for the specified controller (embedded or
extended) for the specified levels as ROAK interrupts or as RORA
interrupts. If the VXI/VME interrupt level is handled as a RORA
interrupt, the local interrupt generation is automatically inhibited
during the interrupt acknowledgment. After device-specific interaction
has caused the deassertion of the interrupt on the backplane, your
application must call
EnableVXIint to re-enable the appropriate
VXI/VME interrupt level.