User manual

Glossary
VXI-MXI-2 User Manual Glossary-4 © National Instruments Corporation
BTO unit Bus Timeout Unit; a functional module that times the duration of
each data transfer and terminates the cycle if the duration is
excessive. Without the termination capability of this module, a
bus master attempt to access a nonexistent slave could result in
an indefinitely long wait for a slave response.
bus master A device that is capable of requesting the Data Transfer Bus
(DTB) for the purpose of accessing a slave device.
byte A grouping of adjacent binary digits operated on as a single unit.
Most commonly consists of eight bits.
C
C Celsius
clearing Replacing the information in a register, storage location, or
storage unit with zeros or blanks.
CLK10 A 10 MHz, ± 100 ppm, individually buffered (to each module
slot), differential ECL system clock that is sourced from Slot 0
of a VXIbus mainframe and distributed to Slots 1 through 12 on
P2. It is distributed to each slot as a single-source, single-
destination signal with a matched delay of under 8 ns.
CMOS Complementary Metal Oxide Semiconductor; a process used in
making chips.
Commander A message-based device which is also a bus master and can
control one or more Servants.
configuration registers A set of registers through which the system can identify a
module device 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.
configuration space The upper 16 KB of A16 space in which the configuration
registers for VXI and MXIbus devices exist.
controller An intelligent device (usually involving a CPU) that is capable
of controlling other devices.