Ram is the internal memory of the computer for storing data program and program results. It is a high speed component in devices that temporarily stores all information. Random Access Memory is volatile that means data is retained in RAM as long as the CPU in switched on. It is a read/write memory which store data until the machine is working. As soon as machine is switched off the data is erased.
Functions
RAM works in conjuction with the Hard-drive which takes core of long-term storage, to provide quick access to files that the computer is actively reading or writing.
There are many basic and main functions of RAM are given below.
Reading Files :- This is also the work of RAM memory. Hard-drive can stores a huge number of data but as compared to RAM it is very slow. RAM has on memory parts so the files load faster than Hard-drive.
Temporary Storage :- That files of the computer or programs which have been used. The RAM saves in a temporary way, which is the main function of the computer RAM.
Loading Applications :-
Loading software application is also the main function of RAM. Any software or application Open in the computer using RAM itself.
How RAM Works
Ram is basically your computers short term memory. Similar to a microprocessor, a memory chip in in an integrated circuit (IC) made of millions of transistors and capacitors. In the most common memory, dynamic random access memory (DRAM), a transistor and a capacitor are pained to create a memory cell, which represents a single bit of data.
Memory is made up of bits arranged on a two dimensional grid.
Memory call are attached onto a silicon water in an array of columns (bitlines) and rows (wordlines). The intersction of a bitline and woedline constitutes the sddress of the memory cell. The memory cells have a whole support infrastructure of other specialized circuits. These circuits perform functions such as :-
1. Identifying each are row and column.
2. Keeping track of the Refresh sequence.
3. Reading and restoring the signal from a cell.
4. Telling a cell whether it should take a change or not (write enable).
Types of RAM
There are basic two types of RAM.
> Static RAM (SRAM)
> Dynamic RAM (DRAM)
1. Static RAM (SRAM)
Static RAM is random access memory that retairs data bits in its memory as as long as power is being supplied. SRAM chips use a matrix of 6-transistors and no capacitors. Transistors do not require power to prevent leakage, so SRAM need not be refreshed on a regular basis. SRAM is thus used as cache memory and has very fast access.
Characteristic of static RAM :-
> Long life
> No need to refresh
> Faster
> Used as cache memory
> Large size
> Expensive
> High power consumption
2. Dynamic RAM (DRAM)
Dynamic RAM, most be continually refreshed in order to maintain the data. DRAM is used for most system memory as it is cheap and small.
Characteristic Of Dynamic RAM :-
> Short data lifetime
> It is slower than SRAM
> Needs to be refreshed continuously
> Used as RAM
> Less expensive
> Less power consumption
> smaller in size
This following are some common types of RAM.
FPM DRAM :- Fast page mode Dynamic Random Access Memory was the original torm of DRAM.
EDO RAM :- Extended Data Out Dynamic Random Access Memory does not wait for all of the processing of the first bit before continuing to the Next one.
SD RAM :- Synchronous Dynamic Random Access Memory takes advantages of the burst mode concept to greatly improve performance.
DDR SDRAM :- Double Data Rate Synchronous Dynamic Random Access Memory is has higher bandwidth, meaning greater speed. It is the next generation of SD RAM.
RD RAM :- Rambus Dynamic Random Access Memory is a radical departure form the previous DRAM architecture.
Credit Card Memory :- It is a proprietary self – contained DRAM memory module that plugs into a special slot for use in notebook computer.
PCMCIA Memory Card :- they are rarely used now a days.
CMOS RAM :- It is a term for the small amount of memory used by a computer. This memory uses asmall battery to provide it with the power it needs to maintain the memory contents.
V RAM :- Video is known as multiport Dynamic Random Access Memory (MP DRAM). It is a type of RAM used for video adapter or 3D accelerators.
Random Access Memory is different from Read Only Memory (ROM). Rom is memory to which programming has been permanently written. Rom cannot be altered, and it’s contents are retained even when the computer has no power. RAM is constantly overwritten when the device is in operation.
