A memory bank is a logical unit of storage in electronics, which is
hardware-dependent. In a
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
, the
memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...
bank may be determined by the
memory controller
The memory controller is a digital circuit that manages the flow of data going to and from the computer's main memory. A memory controller can be a separate chip or integrated into another chip, such as being placed on the same die or as an int ...
along with physical organization of the hardware memory slots. In a typical
synchronous dynamic random-access memory
Synchronous dynamic random-access memory (synchronous dynamic RAM or SDRAM) is any DRAM where the operation of its external pin interface is coordinated by an externally supplied clock signal.
DRAM integrated circuits (ICs) produced from the ...
(SDRAM) or
double data rate SDRAM
Double Data Rate Synchronous Dynamic Random-Access Memory (DDR SDRAM) is a double data rate (DDR) synchronous dynamic random-access memory (SDRAM) class of memory integrated circuits used in computers. DDR SDRAM, also retroactively called DDR1 ...
(DDR SDRAM), a bank consists of multiple rows and columns of storage units, and is usually spread out across several
chips
''CHiPs'' is an American crime drama television series created by Rick Rosner and originally aired on NBC from September 15, 1977, to May 1, 1983. It follows the lives of two motorcycle officers of the California Highway Patrol (CHP). The serie ...
. In a single read or write operation, only one bank is accessed, therefore the number of bits in a column or a row, per bank and per chip, equals the memory bus width in bits (single channel). The size of a bank is further determined by the number of bits in a column and a row, per chip, multiplied by the number of chips in a bank.
Some computers have several identical memory banks of RAM, and use
bank switching
Bank switching is a technique used in computer design to increase the amount of usable memory beyond the amount directly addressable by the processor instructions. It can be used to configure a system differently at different times; for example ...
to switch between them.
Harvard architecture
The Harvard architecture is a computer architecture with separate storage and signal pathways for instructions and data. It contrasts with the von Neumann architecture, where program instructions and data share the same memory and pathways.
...
computers have (at least) two very different banks of memory, one for program storage and other for data storage.
In caching
A memory bank is a part of
cache memory
In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewher ...
that is addressed consecutively in the total set of memory banks, i.e., when data item is stored in bank , data item is stored in bank . Cache memory is divided in banks to evade the effects of the bank cycle time (see above) ''
> missing "bank cycle" definition, above'. When data is stored or retrieved consecutively each bank has enough time to recover before the next request for that bank arrives.
The number of memory modules needed to have the same number of data bits as the bus. A bank can consist of one or more memory modules.
See also
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Bank switching
Bank switching is a technique used in computer design to increase the amount of usable memory beyond the amount directly addressable by the processor instructions. It can be used to configure a system differently at different times; for example ...
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Interleaved memory
In computing, interleaved memory is a design which compensates for the relatively slow speed of dynamic random-access memory (DRAM) or core memory, by spreading memory addresses evenly across memory banks. That way, contiguous memory reads and w ...
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Memory rank
A memory rank is a set of DRAM chips connected to the same chip select, which are therefore accessed simultaneously. In practice all DRAM chips share all of the other command and control signals, and only the chip select pins for each rank are sepa ...
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Memory geometry
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Memory organisation
Further reading
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References
{{Reflist
Computer memory