What is Computer Memory?
In computing, memory refers to a device that is use to store information for immediate use in a computer or related computer hardware device. It typically refers to semiconductor computer memory, specifically metal-oxide-semiconductor memory (MOS),where data is stored within MOS memory cells on a silicon microcircuit chip. The term “memory” is usually synonymous with the term “primary storage”.
Computer memory operates at a high speed, for instance random-access memory(RAM), as a distinction from storage that gives slow-to-access information but offers higher capacities. If needed, contents of the PC memory are often transferred to a secondary storage; a really common way of doing this is often through a memory management technique called virtual storage. An archaic synonym for memory is store.
Storage Type:
The term “memory”, meaning “primary storage” or “main memory”, is often associated with addressable semiconductor memory, i,e. integrated circuits consisting of silicon-based MOS transistors, use for instance as primary storage but also other purposes in computes and other digital electronic devices. There are two main sorts of semiconductor memory, volatile and non-volatile memory are flash memory (used as secondary storage) and ROM, PROM, EPROM and, EEPROM memory (used for storing firmware such as BIOS).
Examples of volatile memory are primary storage, which is usually dynamic random-access memory (DRAM),and fast CPU cache memory ,which is usually static random access memory (SRAM) that’s fast but energy-consuming, offering lower memory areal density than DRAM.
Most semiconductor memory is organized into memory cells or bistable flip-flops, each storing one bit(0 or 1). Flash memory organization includes both one bit per memory cell and multiple bits per cell (called MLC, Multiple Level Cell). The memory cells are grouped into words of fixed word length, for instance 1,2,4,8,16,32,64 or 128bit.each word are often accesses by a binary address of N bit, making it possible to store 2 raised by N words within the memory. This implies that processor registers normally aren’t considered as memory, since they only store one word and don’t include an addressing mechanism.
Volatile memory:
Volatile memory is memory that needs power to take care of the stored information.latest semiconductor volatile memory is either static RAM (SRAM) or dynamic RAM(DRAM). SRAM retains its contents as long because the power is connected and is easier for interfacing, but uses six transistors per bit.Dynamic RAM is more complicated for interfacing and control, needing regular refresh cycles to stop losing its contents,but uses just one transistors and one capacitor per bit, allowing it to succeed in much higher densities and far cheaper per-bit costs.
SRAM isn’t worthwhile for desktop system memory, where DRAM dominates, but is employed for his or her cache memories. SRAM is commonplace in small embedded systems, which could only need tens of kilobytes or less. Forthcoming volatile memory technologies that aim at replacing or competing with SRAM and DRAM include Z-RAM and A-RAM.
Non-volatile memory:
Solid-state drives are one example of a memory device.
Main article: Non volatile memory
Non-volatile memory is memory which will retain the stored information even when not powered. samples of non-volatile memory include ROM (see ROM), non-volatile storage, most sorts of magnetic memory devices (e.g. hard disc drives,floppy disks and magnetic tape), optical discs, and early memory methods like paper and punch cards.
Forthcoming non-volatile memory technologies include FERAM, CBRAM, PRAM, STT-RAM, SONOS, RRAM, racetrack memory, NRAM, 3D Xpoint, and millipede memory.
