Microsoft Word Tutorial | Lesson-2 | Assamese | Learn MS WORD 2007 Lesso...

Microsoft Word Tutorial | Lesson-1 | Assamese | Learn MS WORD 2007 Les...

Know ! what is memory unit of a computer ?

 Memory Unit 

A Memory Unit is a collection of storage cells along with associated circuits needed to transfer information in and out of storage. 

Word 

The memory stores the binary information (1's and 0's) in groups of bits called words. A word in memory is an entity of bits that move in and out of storage. A memory word could be a group of 1's and 0's and should represent variety, an instruction code, one or more alphanumeric characters, or the other binary coded information.

Byte

A group of eight bits is called a byte. Most computer memories use words whose number of bits could be a multiple of 8. Thus a 16-bit word contains two bytes, and a 32-bit word is created from 4 bytes. The capacity of memories in commercial computers is typically stated because the total number of bytes which will be stored. Internal Structure of a Memory Unit The internal structure of a memory unit is specified by the amount of words it contains and also the number of bits in each word. 

Each word in memory is assigned an number, called an address, staring from 0 and continuing with 1, 2, 3, up to 2^k - 1 where k is that the number of address lines. the choice of a particular word inside the memory is finished by applying the k-bit binary address to the address lines.

A decoder inside the memory accepts this address and opens the paths needed to pick out the bits of the required word.  it's customary to visit the quantity of words(or bytes) during a memory with one among the letters:

• K(Kilo) is equals 2¹⁰

• M(Mega) is equals to 2²⁰

• G(Giga) is equals to 2³⁰

Two major sorts of memories are employed in computer systems: Random Access Memory(RAM) and browse Read Only Memory(ROM). These semiconductor memories are classified into Random Access Memories(RAMs) and Sequential Access Memories(SAMs) supported time interval. Memories constructed with shift registers, Charged Coupled Devices (CCDs), or bubble memories are samples of SAMs. RAMs are categorized into ROMs, Read Mostly Memories (RMMs), and skim Write Memories(RWMs). 

ROMs are usually two types: Masked Programmed ROMs and User Programmed PROMs. Two sorts of RMMs are Erasable and Programmable(EPROM) and Electrically Erasable(EEPROM).

RWMs are Static RAM(SRAM) and Dynamic RAM(DRAM). Static RAMs have memory cells as common Flip-Flops. Dynamic RAMs have memory cells that has to be refreshed, read and written periodically to avoid loss of memory cells.