RAM | Definition,Types

 

RAM | Definition & Types

Random access memory (RAM)

Random access memory (RAM) is a volatile memory and loses all its data when the power is turned off. It is the main memory of the computer system that stores data temporarily and allows data to be accessed in any order. Compared to secondary storage, data in RAM can be accessed at a faster speed because it is the computer's internal memory.
RAM is made up of various ICs, which are mounted on a printed circuit board. RAM stores the application programs and data the user is currently working on so that the processor can easily access the required application programs and data in less time. RAM is also called read/write memory because it can perform both read and write operations. RAM is faster than other memory devices like hard disk, floppy disk etc. Programs currently run by computer systems are stored in RAM. RA is volatile and hence, programs and data stored in RAM are lost when the power supply is switched off. The storage capacity of RAM is generally less than that of secondary storage devices.
RAM can be classified into two main types, namely, static RAM (SRAM) and dynamic RAM (DRAM) which can be further divided into different types for storing data. Figure 3.4 shows the classification of RAM memory.

Static RAM
Static RAM (SRAM) is a type of RAM that stores data until the computer system is powered off. SRAM uses several transistors to store a single bit of digital information.

Asynchronous SRAM (ASRAM)
ASRAM performs its operations without the use of a system clock. It uses three signals to work, namely, Chip Select (CS), Write Enable (WE) and Output Enable (OE). The CS signal enables the processor to select memory to perform read and write operations. If the value of the CS signal is equal to zero, the memory is enabled for operation. On the other hand, if the value of the CS signal is one, the memory is disabled and operations such as reading and writing to the ASRAM cannot be performed. The WE signal makes decisions about data, i.e., whether it should be read or written from memory. If the value of the WE signal is equal to zero, then no data can be read or written from the memory. Signal OE is an active low signal that enables the processor to output data. If the value of OE signal is equal to zero, only it will output data.

Burst SRAM (BSRAM)
BSRAM works with the system clock and is also known as synchronous SRAM. BSRAM is typically used with high-speed applications because the read and write cycles are synchronized with the processor's clock cycle. Access-wait times are reduced after the read and write cycles are synchronized with the clock cycle. The speed and cost of BSRAM increases or decreases simultaneously.

Pipeline burst SRAM (PBSRAM)
PBSRAM uses pipeline technology where large amounts of data are broken into different packets containing data. These packets are sequenced in the pipeline and simultaneously sent to memory. PBSRAM can handle large amounts of data at very high speeds. It is the fastest type of SRAM as it can operate at bus rates up to 66 MHz.

Dynamic RAM
DRAM is a RAM that stores data in a storage cell consisting of transistors and capacitors. Unlike SRAM, DRAM needs to be constantly refreshed with a power supply because capacitors tend to discharge. DRAM retains data for a very short time even after the power supply is turned off.

Synchronous DRAM (SDRAM)
SDRAM performs its operations in synchronous mode, i.e. in sync with the clock cycle of the processor bus. It consists of two internal memory banks so that if the address line is sent from the first bank, the address can be read using the second bank. Internal banks are used because reading an address requires charging the row and column address lines SDRAM provides a synchronous interface where it waits for a clock signal before responding to a control input. Generally, it is used with processors to store data in a continuous manner. Sequential form of data storage helps to process more instructions per unit time which increases data access speed.

Rambus DRAM (RDRAM)
Rambus Inc. RDRAM designed by works faster than SDRRAM. It is compact in size and uses 16-bit address bus. It facilitates data transfer at a maximum speed of 800 MHz. It has multiple address and data lines which help to speed up data access. These multiple address and data lines help to perform different read and write operations simultaneously. It is not popular among users due to high cost and low compatibility.

Extended Data out DRAM(EDODRAM)
EDODRAM can access multiple bits at a time that helps to achieve rapid data access rate. It provides the advantage of performing various activities such as reading, writing, etc. at one time

Fast Page Mode DRAM (FPMDRAM)
Using FPMDRM pagging so that the rows and matrix columns are selected by selecting or writing the data address.
Once the data is read, the address of the specified column is extended, so that the user's data can be read the next part. The use of paging concepts at FPDRAM does not allow the bus to work at a speed of more than 66 66 MHz. As a result, reading and writing data from matrix spends a lot of time.

FAQs

1.What is the full form of RAM?
Ans: Random access memory

2 .What is the full form of RAM?
Ans: Read Only memory

3.What is RAM in memory unit?
Ans: RAM (Random Access Memory) is a computing device's hardware that stores the operating system (OS), application programs, and current usage data for quick access by the device's processor.