National Instruments NI-VXI - Manual (Page 99)

Chapter 3 Software Overview
© National Instruments Corporation 3-61 NI-VXI User Manual
low-level VXI/VMEbus access functions will be reported to this
handler. See also the descriptions of
SetBusErrorHandler and
GetBusErrorHandler .
DefaultSoftResetHandler ()
DefaultSoftResetHandler is the sample handler for the Soft Reset
interrupt, and is installed as a default handler when InitVXIlibrary
initializes the NI-VXI software. It increments the global variable
SoftResetRecv . When the Reset bit in the VXI Control register of
the local CPU is written, the VXI interface (if an embedded CPU) and
the VXI register sets are reset (VXI logical address and address base
are retained). The write to the Reset bit causes an interrupt on the local
CPU, which can be handled in any appropriate manner. The CPU
cannot restart operation until the Reset bit is cleared. After the Reset bit
is cleared, the local CPU can go through a reinitialization process or
reboot altogether. If the local CPU is the Resource Manager (and
top-level Commander), the Reset bit should never be written. Writing
the Reset bit of any device should be reserved for the Commander of
the device.
EnableSoftReset must be called to enable writes to the
Reset bit to generate interrupts to the local CPU after the
InitVXIlibrary call.
Note: The Soft Reset interrupt does not apply to VME.
DefaultSysfailHandler (controller)
DefaultSysfailHandler is the sample handler for the Sysfail
interrupt, and is installed as a default handler when InitVXIlibrary
initializes the NI-VXI software. The VXIbus specification requires that
all VXI Commanders monitor the PASSed or FAILed state of their
VXI Servants. When a VXIbus device is in the FAILed state, the
failed device clears its PASS bit (in its Status register) and asserts the
SYSFAIL* signal on the VXIbus backplane. A Sysfail condition
detected on the local CPU generates an interrupt that calls the current
Sysfail interrupt handler. The failed Servant device must be
forced offline or brought back online in an orderly fashion.
DefaultSysfailHandler scans the local CPU Servants and if a
Servant is detected to have failed, the Servant’s Sysfail Inhibit bit in its
Control register is set. In addition, the global variable
SysfailRecv is
incremented.