Memory
A memory is just like a human brain. It is used to store data and
instructions. Computer memory is the storage space in computer where data is to
be processed and instructions required for processing are stored.
The memory is divided into large number of small parts. Each part is
called cell. Each location or cell has a unique address, which varies from zero
to memory size minus one.
For example, if computer has 64k words, then this memory unit has 64 *
1024=65536 memory location. The address of these locations varies from 0 to 65535.
Memory is primarily of three types:
·
Cache Memory
·
Primary Memory/Main Memory
·
Secondary Memory
Cache
Memory
Cache memory is a very high speed semiconductor memory, which can speed
up CPU. It acts as a buffer between the CPU and main memory.
It is used to hold those parts of data and program which are most
frequently used by CPU. The parts of data and programs are transferred from
disk to cache memory by operating system, from where CPU can access them.
Advantage
·
Cache memory is faster than main memory.
·
It consumes less access time as compared to main memory.
·
It stores the program that can be executed within a short period of
time.
·
It stores data for temporary use.
Disadvantage:
·
Cache memory has limited capacity.
·
It is very expensive.
