Glossary
VXI-MIO Series User Manual G-6
National Instruments Corporation
dual-access memory Memory that can be sequentially, but not simultaneously,
accessed by more than one controller or processor. Also known as
shared memory.
dual-ported memory Memory that can be simultaneously accessed by more than one
controller or processor.
dynamic configuration A method of automatically assigning logical addresses to VXIbus
devices at system startup or other configuration times. Each slot
can contain one or more devices. Different devices within a slot
can share address decoding hardware.
dynamically configured A device that has its logical address assigned by the Resource
device Manager. A VXI device initially responds at Logical Address 255
when its MODID line is asserted. The Resource Manager
subsequently assigns it a new logical address, which the device
responds to until powered down.
dynamic range The ratio of the largest signal level a circuit can handle to the
smallest signal level it can handle (usually taken to be the noise
level), normally expressed in dB.
E
ECL Emitter-Coupled Logic
EEPROM electrically erasable programmable read-only memory—ROM
that can be erased with an electrical signal and reprogrammed.
EISA Extended Industry Standard Architecture
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.
event Signals or interrupts generated by a device to notify another
device of an asynchronous event. The contents of events are
device-dependent.
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.
external trigger A voltage pulse from an external source that triggers an event
such as A/D conversion.
EXTREF external reference signal
EXTSTROBE external strobe signal