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

Radius of curvature in differential calculas, find the radius of curvature ...

find the radius of curvature at the point (3,3) at a point x3+xy2-6y2=0?

Define the most common biometrics, What is most common biometrics? Explain ...

What is most common biometrics? Explain in brief. The most common biometrics is as given below: Face geometry (Photo): The computer captures the picture of your face and m

Explain about algebraic simplification, Q. Explain about Algebraic Simplifi...

Q. Explain about Algebraic Simplification? We have already determined algebraic simplification of logic circuit. An algebraic expression can exist in SOP or POS forms.  Let's i

Illustrate working of J-K flip-flop, Q. Illustrate working of J-K flip-flop...

Q. Illustrate working of J-K flip-flop? J-K flip-flop is also a modification of SR flip-flop since it has 2 inputs same as S and R and all possible inputs combinations are vali

What is a heap, What is a heap? The heap is an area of memory that is ...

What is a heap? The heap is an area of memory that is dynamically allocated. As a stack, this may grow and shrink throughout runtime. Not like a stack, a heap is not LIFO show

How putchar function is used within a c program, How putchar function is us...

How putchar function is used within a C Program ? The following program reads each character in the first line of input entered at the terminal's keyboard. It uses putchar to d

Illustrate about sharing of structure and behaviour, Illustrate about Shari...

Illustrate about Sharing of Structure and Behaviour  One of the reasons for the popularity of object-oriented techniques is that they promote sharing at different levels. Inher

Functions for message passing, Functions for Message Passing: MPI proc...

Functions for Message Passing: MPI processes don't share memory space and one process can't directly access other process's variables. Therefore they need some form of communi

What are the types of pipeline hazards, What are the types of pipeline haza...

What are the types of pipeline hazards? The various pipeline hazards are:  1. Data hazard  2. Structural Hazard  3. Control Hazard.

Sets and bags, Task: Sets and bags In mathematics, the notion of multis...

Task: Sets and bags In mathematics, the notion of multiset (or bag) is a generalisation of the notion of set. A bag is a special kind of container in which the items may be

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