address bus


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address bus

[′ad·res ‚bəs]
(computer science)
An internal computer communications channel that carries addresses from the central processing unit to components under the unit's control.

address bus

(processor)
The connections between the CPU and memory which carry the address from/to which the CPU wishes to read or write. The number of bits of address bus determines the maximum size of memory which the processor can access.

See also data bus.

address bus

An internal channel that transmits the RAM location of the data being processed or the instruction being fetched. The number of lines (wires) in the address bus determines the maximum amount of RAM that can be directly accessed by the CPU as each line carries one bit of the address. In 1981, the IBM PC had a limit of one megabyte of RAM because its address bus had 20 lines, and 20 bits represents the number 1,048,576 in binary.

A computer with a 32-bit address bus can directly address 4GB of physical memory, while one with 36 bits can address 64GB. See binary values, address, RAM and IBM PC.


References in periodicals archive ?
In this state, the address of the data from external ROM is fetched first for which "ale" is asserted to latch lower order address bus. Then the control branches to state 501, where the "ale" signal is deactivated.
The two least significant bits of address bus (LSB) are entries for one block of Cache RAM, this block is called LSB Control, aspect presented in fig.
The address and slot map for each channel are connected to a common address bus. This bus bypasses the register files and directly drives the backplane transceivers during bus address cycles.
Mr Springborg said the underground project would address bus and rail congestion for an affordable price.
[2] also looked at combining a serialized-widened bus with differential data encoding and found that it helped on the address bus but not on the data bus.
The microcontroller has an 8-bit data bus and a 16-bit address bus, allowing the use of 64KB of external memory.