User manual

Glossary
VXI-MXI-2 User Manual Glossary-8 © National Instruments Corporation
M
MB Megabytes of memory
m meters
mainframe extender A device such as the VXI-MXI-2 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 operation A device is in master mode if it is performing a bus cycle which
it initiated.
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 device An intelligent device that implements the defined VXIbus
registers and communication protocols. These devices are able to
use Word Serial Protocol to communicate with one another
through communication registers.
MBLT Multiplexed Block Transfer; 8-byte block transfers in which
both the Address bus and the Data bus are used to transfer data.
MITE A National Instruments custom ASIC, a sophisticated dual-
channel DMA controller that incorporates the Synchronous MXI
and VME64 protocols to achieve high-performance block
transfer rates.
MODID Module Identification lines
MSB Most Significant Bit (such as bit 15 in a 16-bit register)