Page 102 - Electrical Engineering Dictionary

branch target buffer (BTB) a buffer that face. This research led to the development of
is used to hold the history of previous branch integrated circuits.
paths taken during the execution of individ-
ual branch instructions. The BTB is used Braun, Karl Ferdinand (1850–1918)
to improve prediction of the correct branch Born: Fulda, Germany
path whenever a branch instruction is en- Braun is best known for his invention of
countered. the oscilloscope and for improvements to
The branch target buffer or branch tar- Marconi’s telegraph. Braun was to share
get cache contains the address of each re- the Nobel Prize in Physics with Marconi in
cent branch instruction (or the instructions 1909. Braun held a number of teaching posts
themselves), the address of the branch “tar- throughout Germany. His research resulted
get” and a record of recent branch directions. in the principle of magnetic coupling, which
The Pentium BTB is organized as an associa- allowed significant improvements in radio
tive cache memory, with the address of the transmission. He discovered crystal recti-
branch instruction as a tag; it stores the most fiers, which were a significant component in
recent destination address plus a two-bit his- early radio sets.
tory field representing the recent history of
the instruction. breadboard a preliminary, experimental
circuit, board, device or group of them. It is
branch target cache See branch target built only to investigate, test, analyze, eval-
buffer. uate, validate, determine feasibility, develop
technical data, and to demonstrate the tech-
nical principles related to a concept, device,
branch voltage the voltage across a
circuit, equipment, or system. It is designed
branch of a circuit.
in a rough experimental form, only for labo-
ratory use, and without regard to final physi-
Branly, Edouard Eugene (1844–1940)
cal appearance of a product.
Born: Amiens, France
Branly is best known for his work in wire-
breadth-first search a search strategy for
less telegraphy. Branly invented the coherer,
tree or trellis search where processing is per-
a detection device for radio waves. Branly
formed breadth first, i.e., the processing for
did much theoretical work in electrostatics,
the entire breadth of the tree/trellis is com-
electrodynamics, and magnetism. He did
pleted before starting the processing for the
not, however, develop the practical side of his
next step forward.
work, hence Marconi and Braun received the
Nobel Prize for work Branly had pioneered.
break frequency the critical frequency
in a frequency - dependent response: espe-
Brattain, Walter (1902–1987) Born: cially that frequency which may separate two
Amoy, China. modes of the response, e.g. the frequency
Brattain is best known as one of the de- that defines where the low frequency region
velopers of the transistor. In 1956 Brattain, ends and the midband response begins.
along with John Bardeen and William Shock-
ley, received the Nobel Prize for their devel- break point See breakpoint.
opment of the point-contact transistor. It was
Brattain who, along with Bardeen, observed break-out box (BOB) a testing device
the significant increase in power output from that allows the designer to switch, cross, and
a metal contact resulting from a small in- tie interface leads. It often has LEDs to per-
crease in current applied through a second mit monitoring of the leads. Typical use is
contact attached to the same germanium sur- for RS-232 interfaces.

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