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

Compare pre-emptive and non-preemptive scheduling policies, Compare pre-emp...

Compare pre-emptive and non-preemptive scheduling policies. We preempt the currently executing process in preemptive scheduling. In non-preemptive we permit the current process

What is the standard template library (stl), A library of container templat...

A library of container templates approved by the ANSI committee for inclusion in the standard C++ specification. A programmer who then launches into a discussion of the generic

Explain the configuration of a step-by-step switching system, With neat dia...

With neat diagrams explains the configuration of a step-by-step switching system. The schematic diagram for an exchange is specified in figure. Each subscriber is associated to

Address phase - computer architecture, Address phase: A PCI bus transa...

Address phase: A PCI bus transaction starts having an address phase. The initiator,  after seeing that it has GNT# and the bus is inactive, drives the target address onto the

The concept of program-parallel computing, The Concept of Process Infor...

The Concept of Process Informally, a method is a program in execution, behind the program has been loaded in the main memory. However, a method is more than just a program code

Block format and disk layout on cd-rom, Q. Block Format and Disk Layout on ...

Q. Block Format and Disk Layout on CD-ROM? A typical block format is displayed in Figure (a). It comprises the subsequent fields: Sync: Sync field identifies beginning o

Classification according to part of instruction and data, Classification ac...

Classification according to part of instruction and data: According to the parts of instruction and data, following parts are identified under this classification: Scal

Communication of request/response - procedural interaction, Explain the Com...

Explain the Communications of Request/Response Communications requirements for message or procedural- based interaction are very similar. Application interaction (client-server

What is a match code, What is a Match Code? Match code is a tool to hel...

What is a Match Code? Match code is a tool to help us to find for data records in the system. Match Codes are an proficient and user-friendly search aid where key of a record i

Microprocessors and digital design, Describe the purpose and operation of R...

Describe the purpose and operation of Register 2 (R2) for the MSP430

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