Glossary
VXI/VME-PCI8022 for Solaris G-2
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National Instruments Corporation
A32 space VXIbus address space equivalent to the VME 4 GB extended address
space.
ACFAIL A VMEbus backplane signal that is asserted when a power failure has
occurred (either AC line source or power supply malfunction), or if it is
necessary to disable the power supply (such as for a high temperature
condition).
address Character code that identifies a specific location (or series of locations)
in memory.
address modifier One of six signals in the VMEbus specification used by VMEbus
masters to indicate the address space in which a data transfer is to take
place.
address space A set of 2n memory locations differentiated from other such sets in
VXI/VMEbus systems by six addressing lines known as address
modifiers. n is the number of address lines required to uniquely specify
a byte location in a given space. Valid numbers for n are 16, 24, and 32.
In VME/VXI, because there are six address modifiers, there are 64
possible address spaces.
address window A portion of address spa ce that can be ac cessed from th e application
program.
ANSI American National Standards Institute
arbitration A process in which a potential bus master gains control over a particular
bus.
asynchronous Not synchronized; not controlled by time signals.
BB bytes
backplane An assembly, typically a printed circuit board, with 96-pin connectors
and signal paths that bus the connector pins. A C-size VXIbus system
will have two sets of bused connectors called J1 and J2. A D-size
VXIbus system will have three sets of bused connectors called J1, J2,
and J3.
BERR* Bus error signal