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 digital versatile disk read only memory, DVD-ROM employs same princ...

DVD-ROM employs same principle as a CD-ROM for reading and writing. However a smaller wavelength laser beam is used. Total capacity of DVD-ROM is 8.5GB. In double-sided DVD-ROM two

What are the different types of bios, The  most common types are the AWARD,...

The  most common types are the AWARD,AMI, AND phoenix

Free memory space to form contiguous block of free space, The OS of a compu...

The OS of a computer might be periodically collect all the free memory space to form contiguous block of free space.  Garbage collection

Drawback of these electromechanical and mechanical computers, Drawback of t...

Drawback of these electromechanical and mechanical computers The basic drawback was: Inertia/friction of moving components had limited speed. The data movement usin

Fundamental components of a microprocessor, Q. Fundamental components of a ...

Q. Fundamental components of a microprocessor? The word 'micro' is used in microphones, microscopes, microwaves, microprocessors, microcomputers, microprogramming, microcodes e

Software architecture of microprocessor, The 68HC11 series is based on the ...

The 68HC11 series is based on the Motorola 6800/1 programming instruction set and hence is a fairly simple 8 bit microprocessor. The internal structure of the 6800/1 is shown below

What is the functionality of remote login, What is the functionality of Rem...

What is the functionality of Remote Login? Remote Login gives similar functionality of telnet, along with the added functionality of not involving a password from trusted cli

Thematic analysis - flash design, Thematic Analysis & Interpretation: ...

Thematic Analysis & Interpretation: The next steps in analysis are to move beyond what is literally there in the image (formal visual elements) and examine the meaning they re

What do you mean by communication traffic, Q. What do you mean by Communica...

Q. What do you mean by Communication Traffic? Communication Traffic offers a pictorial view of communication traffic in interconnection network with respect to time in progress

What are the functions of dispatcher, What are the functions of dispatcher?...

What are the functions of dispatcher? There are four fuctions of dispatcher:- A)  Equal distribution of transaction load to the work processes.  B) Management of buffer a

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