Page 401 - A Practical Guide from Design Planning to Manufacturing

Glossary 371

of a semiconductor. This gate wire separates two doped regions in the semi-
conductor called the source and the drain. The electric field from the gate pen-
etrates the semiconductor and determines whether current will flow between
the source and the drain.

MFLOPS Million floating-point operations per second.
Microarchitecture The overall design details of a processor that are not visi-
ble to the software. Microarchitectural choices largely determine the perform-
ance of a processor. Some examples of these design choices are pipeline length,
instruction issue width, methods to resolve control and data dependencies, and
the design of the memory hierarchy.
Microcode Programs of low-level steps performed by the processor to execute
complex machine language instructions or handle special events such as excep-
tions or processor reset. These programs are stored in a read-only memory
array, the microcode ROM.
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Micrometer (Micron, µm) One millionth (10 ) of a meter.
Microprocessor An integrated circuit capable of executing a stored series of
instructions from memory and writing results to memory.
Microvias Small laser-drilled vias connecting levels of package interconnect.
Million floating-point operations per second (MFLOPS) A measure of floating-
point performance. This metric can be deceiving since different floating-point
operations require different amounts of computation and peak MFLOPS may
be far higher than the rate achieved by any real program.
Million instructions per second (MIPS) A measure of computer performance.
This metric can be deceiving since different computers support different machine
language instructions, different instructions require different amounts of com-
putation, and peak MIPS may be far higher than the rate achieved by any real
program. Also referred to as meaningless indicator of processor speed.
Minimal sum The simplest sum-of-products form of a logic function.
MIPS Million instructions per second.
Moore’s law The trend that maximum number of components that can be fab-
ricated on an integrated circuits typically doubles every 2 years. This trend has
allowed the semiconductor industry to quickly increase performance while at
the same time reducing cost.
MOSFET Metal oxide semiconductor field-effect transistor.

Motherboard The main printed circuit board of a computer.
Multichip module (MCM) An integrated circuit package containing multiple die.
Mux A multiplexer circuit that routes one of multiple inputs to its output.
NAND A logic function that is only false if all its inputs are true.
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Nanometer (nm) One billionth (10 ) of a meter.