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 respects the advance builds, Describe your choice specifically and fu...

Describe your choice specifically and fully, explaining and discussing at length in what respects the advance builds upon or departs from present technology or practice and the sev

What are the steps involved in authentication, What are the steps involved ...

What are the steps involved in authentication? Steps in Authentication The control over the access of the resources in the repository is exercised in two steps namely Auth

What is the difference among a canvas and a scroll panel, Canvas is a compo...

Canvas is a component. ScrollPanel is a container. Canvas is a rectangular area where the application can draw or trap input events. ScrollPane executes horizontal and vertical scr

What happens if acknowledge() is called within a transaction, As per the JM...

As per the JMS specification, when you are in a transaction, the acknowledge Mode is ignored. If acknowledge() is known as within a transaction, it is ignored.

Explain about batch system, Q. Explain about Batch System? A number...

Q. Explain about Batch System? A number of computer systems only did one thing at a time. They had a list of computer system can be dedicated to a single program till its c

Describe how a mobile terminating call, Problem: (a) Describe how a Mob...

Problem: (a) Describe how a Mobile Terminating call, from a PSTN phone, is processed in a GSM network. Illustrate your answer with a diagram. (b) What is a GPRS Support node

Chemistry, application problems on electrochemical series

application problems on electrochemical series

What is core dump, Raises when accessing an unassigned memory location acce...

Raises when accessing an unassigned memory location accessing a null pointer

Define top-down parsing techniques, Define Top-down parsing Techniques ...

Define Top-down parsing Techniques Top-down parsing can be observed as an attempt to find left-most derivations of an input-stream through searching for parse trees using a top

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