Basics of Memory and its type - rlmdtechnical

What is MEMORY:

Memory means data storage in the form of chips, and the word storage refers to memory located in tapes and disks. However, the meaning of memory is taken as short hand of physical memory, which means chips that can store data. Some computers use virtual memory, which increases physical memory on the hard disk.

Each computer comes with some fixed amount of physical memory. Which is called main memory or RAM.

Think of main memory as an array in which every box can store single byte information. A computer whose memory is 1 megabyte. Can store information of 1 Million bytes.

Memory Manufacturers Kingston, Rambus, Crucial, Samsung, PNY, Micron, Centon.

MEMORY TERMINOLOGY:

Memory Speed: It is measured in nanoseconds. This is the time at which store data is accessed in memory. (2 ns-80 ns).

Parity: An easy way in which error in memory can be checked.

ECC: It is used for memory correction.

MEMORY BANKS:

This is a socket where memory is installed.

Example: 4 bank can install 8 MB memory, so total 32 MB memory.

There are several types of memory:

ROM computer always keeps ROM store in small amount, which contains instructions to start the computer. Nothing can be written to ROM like RAM. It is non-volatile, that is, information is stored in memory even when computer is turned off.

PROM (Programmable read-only memory):

PROM is a memory chip on which data can be written only once. Once a program is written to PROM, it is always located there. Unlike RAM, data remains safe even after the computer is turned off in PROM. The difference between PROM and ROM (read-only memory) is that PROM is created as an empty memory, while ROM is programmed only when created. Writing a data to a PROM chip requires a specific device called the PROM programmer or PROM burner. The process of programming a PROM is sometimes called a burning of a PROM.

EPROM (erasable Programmable read-only memory):

There is a specific type of PROM that is erase by placing it against an ultra-violet light. Once erase is done it can be reprogrammed. EPROM is also similar to PROM, but requires electricity to erase it.

EEPROM (Electrically erasable programmable read-only memory):

This is a specific type of PROM that can be erase by electrical charge. Like other types of PROMs, EEPROM also retains data even after power off. Like other ROMs, EEPROM is not as fast as ROM. EEPROM (flash memory) is similar to flash memory (also called flash EEPROM). The main difference in this is that in EEPROM, data can be written or read one byte, while in flash memory, data can be written or read in a block. This makes flash memory faster in speed.

RAM (Random Access Memory):

A volatile storage area is used by the CPU. Before the program is run, it is loaded into memory which allows the CPU to directly access the program. Memory is required for any computer and 64MB of memory is required for your IBM or macintosh.

RAM is the same as man memory. RAM, when used on its own, means reading and writing memory, meaning that you can both read and write data from RAM. Most of the RAM is volatile, which means that it needs a constant flow of power to keep the data secure. The data in the RAM is erased as soon as the power is turned off.

Types of RAM

SRAM (Static random-access memory):

There is a type of memory that is much faster and more reliable than DRAM (dynamic RAM). The word static is derived from the fact that it does not need to be refreshed like dynamic RAM. Where RAM has an access-time of 60 Nano-seconds, SRAM can provide a reduced access time of up to 10 nano-seconds. Additionally, its cycle-time is much shorter than DRAM. Because it does not have to stop between accesses. Its production is more expensive than DRAM. Due to its high cost, SRAM is often used similar to memory cache.

DRAM stands for:

Dynamic is from random-access memory that is used in most personal computers. 

Types of DRAM packages and DRAM memory:

LAPTOP memory:

SODIMM (Small outline DIMM):

There is a smaller version of DIMM, commonly used in notebook computers. 144 SODIMM pins which support full transfer of 64 bit.

FPM RAM (Fast Page Mode RAM):

A type of dynamic RAM that allows fast access to data in a row or page. The function of the page-mode memory is to eliminate the need for a row address if the data accessed is located in the previous row. This is sometimes called page mode memory.

SIMM (single-in-line memory module):

There is a small circuit board consisting of a cluster of memory chips. The SIMM consists of 8 (on Macintosh) or 9 (on PC) RAM chips. The 9th chip on PC is often used for Parity error checking. Unlike memory chips, SIMM is measured in bytes rather than bits. Installing a SIMM is easier than a memory chip. A SIMM is of 30 or 72 pins. 

EDODRAM (Extended Data Output Dynamic RAM):

There is a type of DRAM that is faster than DRAM. Unlike DRAM, which can only access one block of data at a time, EDORAM starts fetching the next block of memory at the same time the previous block is sent to the CPU. 

DIMM (Dual in-line memory module):

There is a small circuit board containing memory chips. The SIMM has a 320-bit path for memory chips, while DIMM requires a 64-bit path, so you can install two SIMMs at a time. You can only install one at a time in DIMM. The DIMM consists of 168 pins.

SDRAM (Synchronous DRAM):

New type of DRAM which is much faster than memory. SDRAM in reality synchronizes itself with the CPU's bus and has the ability to run at a speed of 133 MHz. Ja is three times faster than FPMRAM and two times faster than FDODRAM. SDRAM is being used in place of EDODRAM in many new computers. SDRAM provides data in high speed burst. .

DDRSDRAM (Double Data Rate Synchronous DRAM):

A type of SDRAM that facilitates data transfer at both ends of each clock cycle, effectively doubling the memory data. DDR-SDRAM is also known as SDRAMII.

RIMM (Rambus Inline Memory Module):

Memory module used with RDRAM chips. It is similar to the DIMM package, but has a different type of pin setting. Rambus fired RIMM like a word. It is a term used for modules using the Rambus technique. It is also sometimes mistakenly used for the Rambus Inline Memory Module. The RIMM consists of 184 pins. All sockets should be used in RIMM Installation. RDRAM (Rambus DRAM) is a type of memory (DRAM) used by Rambus, Inc. , And use C-RIMM to terminate banks.

RDRAM (Rambus DRAM):

It is a type of memory (DRAM) created by Rambus. The current memory technology used in PC's or computers transfers data at speeds of 100 MHz, while RDRAM transfers data at speeds of 300 MHz. In 1997 Intel announced that it would license Rambus technology to be installed in its future motherboards. Memory from

Rambus technology became a standard for architecture. But some computer manufacturers are working on different memory architecture. Called Sync Link DRAM (SLDKAMS)

In some Graphic accelerator boards, ADRAM is being used instead of VRAM. Intel Pen Pentium III Xenon processor since late 1999 and Pen

Intel pentium III Xenon processor # Bir Pentium IV processor # RDRAM was used. Working for a new version of Intel and Rambus RDRAM is called nPRAM, and which will transfer data at a speed of 1600 MHz.

SIMM and DIMM sockets

SLDRAM (Sync Link DRAM):

The consortium of some computer manufacturers called Sync Link consortium developed a new type of memory. Which is called SLDRAM. SLDRAM is competing against Rambus Memory (DRAM) for the future PC memory architecture. RDRAM chips now video boards

And other devices have started to be installed, but SLDRAM is still on paper, that is, imaginary. Intel backs IRDRAM, ie supports. Therefore, SLDRAM is not yet such an essential technology.