Glossary
© National Instruments Corporation
Glossary-3
VXI-SB2020 and NI-VXI for Solaris
configuration
A set of registers through which the system can identify a module device
registers
type, model, manufacturer, address space, and memory requirements. In
order to support automatic system and memory configuration, the VXIbus
specification requires that all VXIbus devices have a set of such registers.
D
DACK
DMA Acknowledge
daisy-chain
A method of propagating signals along a bus, in which the devices are
prioritized on the basis of their position on the bus.
Data Transfer Bus
DTB; one of four buses on the VMEbus backplane. The DTB is used by a
bus master to transfer binary data between itself and a slave device.
DIP
Dual Inline Package
DMA
Direct Memory Access; a method by which data is transferred between
devices and internal memory without intervention of the central processing
unit.
DRQ
DMA Request
DTB
See Data Transfer Bus.
dynamic
A method of automatically assigning logical addresses to VXIbus devices
configuration
at system startup or other configuration times.
dynamically
A device that has its logical address assigned by the Resource Manager.
configured device
A VXI device initially responds at Logical Address 255 when its MODID
line is asserted. A MXIbus device responds at Logical Address 255 during
a priority select cycle. The Resource Manager subsequently assigns it a
new logical address, which the device responds to until powered down.
E
ECL
Emitter-Coupled Logic
embedded
An intelligent CPU (controller) interface plugged directly into the VXI
controller
backplane, giving it direct access to the VXIbus. It must have all of its
required VXI interface capabilities built in.
EMI
Electromagnetic Interference
external controller
In this configuration, a plug-in interface board in a computer is connected
to the VXI mainframe via one or more VXIbus extended controllers. The
computer then exerts overall control over VXIbus system operations.
