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

Show the process management for parallel virtual machine, Q. Show the Proce...

Q. Show the Process Management for parallel virtual machine? Process Management  int pvm_mytid( void ) Returns the tid of the calling process. Tid values les

Simulated annealing - artificial intelligence, Simulated Annealing: On...

Simulated Annealing: One way to get around the problem of local maxima, and related problems like ridges and plateaux in hill climbing is to allow the agent to go downhill to

Explain bus, Define bus. When a word of data is transferred among units...

Define bus. When a word of data is transferred among units, all the bits are transferred in parallel over a set of lines called bus. In addition to the lines that take the data

Which is not a valid page replacement policy, Which is not a valid page rep...

Which is not a valid page replacement policy? Ans. RU policy (Recurrently used) is not a valid page replacement policy.

What is charge-coupled devices, Q. What is Charge-coupled Devices? CCDs...

Q. What is Charge-coupled Devices? CCDs are employed for storing information. They have arrays of cells that can hold charge packets of electron. A word is signified by a set o

Struct and class, https://dl.dropbox.com/u/41918180/Images/Pro%202/2.png ...

https://dl.dropbox.com/u/41918180/Images/Pro%202/2.png https://dl.dropbox.com/u/41918180/Images/Pro%202/3.png https://dl.dropbox.com/u/41918180/Images/Pro%202/4.png">https://dl.d

Develop a regular expression for integer and identifier, Develop a regular ...

Develop a regular expression for Integer and Identifier (i) A regular expression for integer is [+ | -] (d)+ (ii) A regular expression for identifier is l(l | d)*

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

Which types of software programs are usually supported, Which types of soft...

Which types of software programs are usually supported? Our organization is unique in that we are very flexible and can meet most client requires relative to the integration of

Develop a regular expression for integer & real number, Develop a regular e...

Develop a regular expression for (i) Integer (ii) Real number (i) A regular expression for integer is [+ | -] (d)+ (ii) A regular expression for real number is [+

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