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

Convert the octal number 7401 to binary, Convert the octal number 7401 to B...

Convert the octal number 7401 to Binary. Ans. Octal number 7401 to Binary conversion: Every octal digit represents 3 binary digits. To change an octal number to binary number,

Perform the subtraction using 1's complement, Perform the subtraction using...

Perform the subtraction using 1's complement of 11001 - 10110 Ans. 11001 - 10110 = X - Y                            X = 11001 1's complement of Y = 01001

Explain the basic syntactic constructs through reductions, Recognition of b...

Recognition of basic syntactic constructs through reductions, this task is performed by? By Syntax analysis, recognition of fundamental syntactic constructs through reductions

C, Drawbacks of linear arrays

Drawbacks of linear arrays

Computer to computer transmission of structured data, Computer to computer ...

Computer to computer transmission of structured data using standardised documentation is known as Electronic data interchange (EDI).

Define the concept of inheritance, Define the concept of Inheritance I...

Define the concept of Inheritance Inheritance is property of reusing the code within the object oriented development. While modelling, we look at the all the classes, and try

Explain the handshaking signals, a. Explain the hardware mechanism for hand...

a. Explain the hardware mechanism for handling multiple interrupt requests. b. What are handshaking signals? Describe the handshake control of data transfer during input and out

What is cmp instruction, What is CMP instruction Comparison instruction...

What is CMP instruction Comparison instruction (CMP) is a subtraction that changes only the flag bits; destination operand never changes. A comparison is useful for checking th

Abap/4 dictionary structures without an underlying database, It is not poss...

It is not possible to use ABAP/4 Dictionary Structures without an underlying database using LDB. True.  You can use additionally related tables, along with the tables explaine

In order to concatenate strings only for output purposes, In order to conca...

In order to concatenate strings only for output purposes which command can be used in conjunction with the 'Write' statement. NO-GAP command.

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