Chapter 3 Software Overview
NI-VXI User Manual
3-60
© National Instruments Corporation
The following paragraphs describe the system interrupt handler
functions and default handlers. The descriptions are presented at a
functional level describing the operation of each of the functions. The
functions are grouped by area of functionality.
AssertSysreset (controller, mode)
AssertSysreset
asserts the SYSRESET* signal on the specified
controller. You can use this function to reset the local CPU, individual
mainframes, all mainframes, or the entire system. If you reset the
system but not the local CPU, you will need to re-execute all device
configuration programs.
Note:
Due to the operation of some operating systems, not all platforms support
resetting the local CPU.
DefaultACfailHandler (controller)
DefaultACfailHandler
is the sample handler for the ACfail
interrupt, and is installed as a default handler when
InitVXIlibrary
initializes the NI-VXI software. It increments the global variable
ACfailRecv
. The VXI/VMEbus specification allows for a minimum
amount of time after a power failure condition occurs for the system to
remain operational. The detection of a power failure in a VXI/VME
system asserts the backplane signal ACFAIL*. An ACfail condition
detected on the local CPU generates an interrupt that calls the current
ACfail interrupt handler. Your application can take any appropriate
action within the allotted time period before complete power failure.
Your application must then call
EnableACfail
to enable ACfail
interrupts after the
InitVXIlibrary
call.
DefaultBusErrorHandler ()
DefaultBusErrorHandler
is the sample handler for the bus error
exception, and is installed as a default handler when
InitVXIlibrary
initializes the NI-VXI software. During an access to the VXI/VMEbus,
the BERR* signal (bus error) is asserted to end the bus cycle if the
address or mode of access is determined to be invalid. The bus error
exception condition generates an exception on the local CPU, which
can be trapped by the bus error handler. Your application should
include a retry mechanism if it is possible for a particular access to
generate bus errors at times and valid results at other times. Because
bus errors can occur at any time, a corresponding enable and disable
function is not possible. Notice that only BERRs occurring via
