Page 49 - Engineering Digital Design

20 CHAPTER 1 / INTRODUCTORY REMARKS AND GLOSSARY

Mixed-rail output: dual, logically equal outputs of a device (e.g., a flip-flop) where one
output is issued active high while the other is issued active low, but the two are not issued
simultaneously.
Mnemonic: a short single group of symbols (usually letters) that are used to convey a
meaning.
Mnemonic state diagram: a fully documented state diagram.
Model: the means by which the major components and their interconnections are repre-
sented for a digital machine or system.
Module: a device that performs a specific function and that can be added to or removed
from a system to alter the system's capability. A common example is a full adder.
Modulus-n counter: (see divide-by-n counter)
Monad: a minterm (or maxterm) that is not logically adjacent to any other minterm (or
maxterm).
Moore machine: a sequential machine that conforms to the Moore model.
Moore model: a degenerate form of the Mealy (general) model in which the output state
depends only on the present state.
Moore output: an unconditional output.
MOS: metal-oxide-semiconductor.
MOSFET: metal-oxide-semiconductor field effect transistor.
Most significant bit (MSB): the extreme left bit of a binary word that has the highest
positional weight.
MSB: most significant bit.
MSD: most significant digit.
MSI: medium scale integration.
MTBF: mean time between failures.
Muller C module: a rendezvous module (RMOD).
Multilevel logic minimization: minimization involving more than two levels of path
delay as, for example, that resulting from XOR-type patterns in K-maps.
Multiple-output minimization: optimization of more than one output expression from
the same logic device.
Multiplex: to select or gate (on a time-shared basis) data from two or more sources onto
a single line or transmission path.
Multiplexer: a device that multiplexes data.
Multiplicand: the number being multiplied by the multiplier.
Multiplier: a combinational logic device that will multiply two binary numbers. Also,
the number being used to multiply the multiplicand.
Mutually exclusive requirement: a requirement in state diagram construction that for-
bids overlapping branching conditions (BCs) — i.e., it forbids the use of BCs shared
between two or more branching paths.
MUX: multiplexer.
NAND-centered basic cell: cross-coupled NAND gates forming a basic cell.
NAND gate: a physical device that performs the electrical equivalent of the NOT AND
function.
NAND/INV logic: combinational logic consisting exclusively of NAND gates and in-
verters.
Natural binary code: a code for which the bits are positioned in a binary word according
to their positional weight in polynomial notation.