What is dynamic random access memory, Computer Engineering

Assignment Help:

Q. What is Dynamic Random Access Memory?

RAM technology is divided into 2 technologies: Static and dynamic. A dynamic RAM (DRAM) is made with cells which store data as charge on capacitors. Absence or presence of charge on capacitor is interpreted as binary 1 or 0. Since capacitors have a natural tendency to discharge, dynamic RAM needs periodic charge refreshing to maintain data storage. Term dynamic corresponds to this tendency of stored charge to leak away even with power continuously applied.

Figure below is a typical DRAM structure for an individual cell which stores one bit. The address line is activated when bit value from this cell is to be read or written.  Transistor acts as a switch which is closed (allowing current to flow) if a voltage is applied to address line and open (no current flows) if no voltage is present on address line.

2157_What is Dynamic Random Access Memory.png

For write operation a voltage signal is applied to bit line; a high voltage represents 1 and a low voltage represents 0.  A signal is then applied to address line allowing a charge to be transferred to capacitor. 

For read operation when address line is selected transistor turns on and charge stored on capacitor is fed out onto a bit line and to the sense amplifier. Sense amplifier compares capacitor voltage to a reference value and decides if cell contains logic 1 or logic 0.  The read out from cell discharges the capacitor that should be restored to complete operation. 

Even though the DRAM cell is used to store a single bit (0 or 1) it is necessary an analog device. Capacitor can store any charge value within a range. A threshold value determines whether charge is interpreted as 1 or 0.


Related Discussions:- What is dynamic random access memory

What is matrix addressing mode, What is Matrix Addressing Mode. Ans. M...

What is Matrix Addressing Mode. Ans. Matrix Addressing Mode: The arrangement which needs the fewest address lines is a square array of n rows and n columns for a whole memory

Types of security features employed in client server network, What are the ...

What are the types of security features employed in client server kinds of network? Security features employed in Client-Server types of network are as illustrated below: a)

Explain structure of control unit, Q. Explain Structure of Control Unit? ...

Q. Explain Structure of Control Unit? A control unit has a set of input values on the foundation of which it produces an output control signal which in turn performs micro-ope

Applications of generic framework for electronic commerce, How are the appl...

How are the applications of generic framework for electronic commerce performed? To perform applications, this is essential to have Supporting Information and Organizational In

Features of hyper-threading, The salient features of hyper threading are: ...

The salient features of hyper threading are: i)  Improved support for multi-threaded code, permitting multiple threads to run concurrently. ii) Response time and improved rea

What is a microinstruction, What is a microinstruction? Each word in co...

What is a microinstruction? Each word in control memory having within it a microinstruction.  The microinstruction specifies one or more micro-operations for the system.  A seq

Special theory of relativty, michelson-morley experiment-motivation and exp...

michelson-morley experiment-motivation and experimental setup

What are the ways to truncate guard bits, What are the ways to truncate gua...

What are the ways to truncate guard bits? 1. Chopping 2. Von Neumann rounding 3. Rounding procedure.

What are the types of smart cards utilized in e-commerce, What are the type...

What are the types of smart cards utilized in e-commerce? Usually, there are two types of smart cards as: Memory smart cards, that can be viewed by minuscule removable read

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd