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

Can we use flow logic control key words in abap/4, Can we use flow logic co...

Can we use flow logic control key words in ABAP/4 and vice-versa The flow control  of a dynpro having os a few statements that syntactically ressemble ABAP/4  statements .Thou

Distinguish between ROM, Distinguish between ROM, PROM, EPROM, EEPROM. ...

Distinguish between ROM, PROM, EPROM, EEPROM. Ans: ROM: It also called Read Only Memory is a Permanent Memory. The data is permanently stored and cannot be changed in Perm

What is a pointer, What is a pointer? The register or memory location t...

What is a pointer? The register or memory location that having the address of an operand is known as a pointer.

Performance analysis, In order to calculate the performance of the program,...

In order to calculate the performance of the program, the normal form of analysis of the program is to simply measure the total amount of CPU time needed to implement the various p

Posix, POSIX is the IEEE's Portable Operating System Interface for Computer...

POSIX is the IEEE's Portable Operating System Interface for Computer Environments. The standard provides compliances criteria for operating system services and is designed to allow

Reference table and a reference field, A field containing currency amounts ...

A field containing currency amounts (data type CURR) must be assigned to a reference table and a reference field. Explain. As a reference table, a system having all the valid

Medical diagnosis program, Diagnosis: Medical diagnosis program bases on p...

Diagnosis: Medical diagnosis program bases on probabilistic analysis have been able to perform at the level of an expert physician tin several areas of medicine. Heckerman(1981)

How to create a new object order preference, 1. In an ASCII editor, make an...

1. In an ASCII editor, make an empty text file with the extension .ord. 2. Save the file in the Dat folder of the project. 3. Click To o l s > G UI R e c o r d O p t i o n s

Differences b/w user level and kernel supported threads, What are the diffe...

What are the differences between user level threads and kernel supported threads? A thread, sometimes termed a lightweight process (LWP), is a fundamental unit of CPU utilizati

Flowchart, how can we find compound interest through flowchart

how can we find compound interest through flowchart

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