Glossary
© National Instruments Corporation Glossary-7 VXI-MXI User Manual
M
MB megabytes of memory
m meters
Mainframe Extender A device such as the VXI-MXI that interfaces a VXIbus mainframe to an
interconnect bus. It routes bus transactions from the VXIbus to the
interconnect bus or vice versa. A mainframe extender has a set of registers
that defines the routing mechanisms for data transfers, interrupts, triggers,
and utility bus signals, and has optional VXIbus Slot 0 capability.
Mapping Establishing a range of address space for a one-to-one correspondence
between each address in the window and an access in VXIbus memory.
Master A functional part of a MXI/VME/VXIbus device that initiates data
transfers on the backplane. A transfer can be either a read or a write.
Master-Mode A device is in master mode if it is performing a bus cycle.
Operation
MBytes/s One million bytes per second; a measure of data transfer rate.
Memory Device A VXIbus device that not only has configuration registers, but also has
memory that is accessible through addresses on the VME/VXI data
transfer bus.
Message-Based An intelligent device that implements the defined VXIbus registers and
Device communication protocols. These devices are able to use Word Serial
Protocol to communicate with one another through communication
registers.
MODID A set of signal lines on the VXI backplane that VXI systems use to
identify which modules are located in which slots in the mainframe.
MSB Most Significant Bit (bit 15 in a 16-bit register)
MTBF Mean Time Between Failure
Multiframe A system consisting of more than one mainframe connected together to act
as one; it can have multiple Slot 0 devices but only one global Resource
Manager.
MXIbus Multisystem eXtension Interface Bus; a high-performance communication
link that interconnects devices using round, flexible cables.
MXIbus System A functional module that has arbiter, daisy-chain driver, and MXIbus
Controller cycle timeout responsibility. Always the first device in the MXIbus
daisy-chain.