Data Bus (data path) Definition/Meaning:
A group of signal lines used to transmit data in parallel
from one element of a computer to another. The number of lines in the group is
the width of the data bus, each line being capable of transferring one bit of
information. In a mainframe the width of the data bus is typically equal to the
word length, i.e. 32, 48, or 64 bits. In a microcomputer the width is typically
4. 8, or 16 bits. The data bus used to interconnect LSI components need not have
the same width as is used on the chips themselves. For example, a processor with
an internal data bus width of 16 bits could be designed to transmit information
over an 8-bit-wide external data bus. Such processors are said to use a
multiplexed data bus (see multiplexed bus). The wider the data bus, the higher
the potential performance of the system, since more information is transmitted
in parallel with a wider data bus. Narrower data buses in general degrade
performance but are less costly to implement, A multiplexed data bus is often
chosen to reduce the number of pins needed on an integrated circuit for the data
bus.
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