User manual

Chapter 7 VXIplug&play for the VXI-MXI-2
VXI-MXI-2 User Manual 7-6 © National Instruments Corporation
This type of system configuration is recommended if you have one of
the following situations:
• A VXIbus mainframe with only slave devices and no masters.
Without bus masters, there is no chance for deadlock. You can
configure the VXI-MXI-2 devices in this mainframe for normal
operating mode.
• A VXIbus mainframe with both masters and slaves, but the
masters communicate only with the slaves in their mainframe. The
masters never attempt transfers across the MXIbus, so there is no
chance for deadlock when a MXIbus master attempts a transfer
into the VXIbus mainframe. You can configure the VXI-MXI-2
devices in this mainframe for normal operating mode.
• A VXIbus mainframe in which all masters that perform cycles
across the MXIbus support the VME64 RETRY protocol. You can
configure the VXI-MXI-2 devices in this mainframe for normal
operating mode because all masters that could cause a deadlock
will automatically retry the operation.
In Chapter 5, Register Descriptions, the INTLCK bit is described in the
VXI-MXI-2 Control Register (VMCR) section. You can use this bit to
enable the interlocked mode of arbitration. However, you may prefer to
have the VXI-MXI-2 automatically enable interlocked mode during its
self-configuration, so that you do not need to access the INTLCK bit at
each power-on. Interlocked mode is disabled in the default
configuration of the VXI-MXI-2.