Glossary
G-4
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D
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.
DRAM
Dynamic RAM
driver window
A region of PCI address space that is decoded by the PCI-MXI-2 for use by
the NI-VXI software.
DTACK*
Data Acknowledge signal
DTB
dynamically configured
device
A device that has its logical address assigned by the Resource Manager. 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.
dynamic configuration
A method of automatically assigning logical addresses to VXIbus devices
at system startup or other configuration times.
E
ECL
Emitter-Coupled Logic
EEPROM
Electronically Erasable Programmable Read Only Memory
embedded controller
An intelligent CPU (controller) interface plugged directly into the VXI
backplane, giving it direct access to the VXIbus. It must have all of its
required VXI interface capabilities built in.
EMC
Electromechanical Compliance