Page 389 - A Practical Guide from Design Planning to Manufacturing

Glossary 359

traditional binary encoding but makes conversion to and from decimal notation
simpler.
Binary intensity mask (BIM) Aphotolithography mask containing only two types
of regions: those that transmit light and those that do not. See phase-shift mask.
BIOS Basic input output system.

Bipolar junction transistor (BJT) A transistor constructed of two P-N junctions.
Charges emitted across one junction can be collected by the other. The voltage
on the base in between the junctions can amplify or inhibit this effect.
BIST Built-in self test.
Bit pitch The fixed height of all the layout cells drawn to create repeated
layout for several bits of data requiring the same logic. By drawing all the cells
to have the same height, assembly of multiple rows of cells is made more
efficient.

Bit A single binary digit. A bit can only be one of two values.
BJT Bipolar junction transistor.
Blue screen of death (BSOD) The blue error screen shown by Microsoft
Windows upon an irrecoverable error.
Bonded etched back silicon on insulator (BESOI) A type of SOI wafer created
by forming a layer of insulation on top of one wafer and bonding that wafer face-
down to another. The wafer is then etched back to leave only a thin layer of sil-
icon on top of the insulator.
Boundary scan A scan chain connecting the input and output drivers of an
integrated circuit. Connecting the boundary scan chains of different ICs on a
motherboard allows tests of the board independent of the components.
Branch instruction A computer instruction that specifies a test condition and
can redirect program execution to a target address based on that test.
Branch prediction A microarchitectural design feature that improves per-
formance by predicting whether a branch instruction will redirect program flow
or not based on its past behavior. If these predictions are usually correct, the
time saved in executing branches can outweigh the added time required when
a prediction is wrong.
Branch target buffer (BTB) A memory cache supporting branch prediction by
holding information on the past behavior of recent branches and their target
addresses.
Braze To solder two pieces of metal together using a hard high-temperature
soldering material usually composed of copper and zinc.
BSOD Blue screen of death.
BTB Branch target buffer.
BTX Balanced technology extended.