The Modern Memory


Sci Tech Nov 06, 2014

How RRAM is all set to create a revolution?

‘RAM’ AND ITS TYPES

Many people know RAM as just “Random Access Memory”. Some people would additionally know it as the one used to store the commands given by the user. Most of the people do not know the internals of a RAM.

Based on the build technology, there are two types of RAM. They are,

  • Static RAM (SRAM)
  • Dynamic RAM (DRAM)

SRAM is expensive to produce but is faster than DRAM and it is used as cache memory of the CPU. In general the RAM used in PCs is the DRAM. DRAM consists of a transistor– capacitor pair, which together comprises a memory cell. Both are volatile forms of memory and they lose the data once the electric charge is turned off.

 EVOLUTION OF RAM

The first form of RAM was the William’s tube (in 1947). It stored data in electrically charged spots in cathode ray tube. Following it, came the Magnetic core memory. Here, the memory consists of an array of Ferrite Toroids (or cores).  A core is required for each bit of memory. During mid-1970’s came the DRAM, developed by Robert H. Dennard, which has been predominantly used since then. This allowed the replacement of the 4 or 6 pair transistors by a single transistor.

William's Tube (Photo by ArnoldReinhold - Own work/ CC BY-SA 3.0)
Magnetic core memory

Now everyone can observe that technology is developing at a much faster rate than in the past. It was just months before that we had a terabyte of storage in hard disk. Now a group of scientists has something better in store for us. Yes, the researchers at Rice University have come up with a new type of RAM called the Resistive Random Access Memory (or the RRAM).

Flash memory storage (Photo by Evan-Amos - Own work/ Public Domain) 

THE ‘RESISTIVE RAM'

Normally in a RAM, a memory cell has a storage charge of 1 or 0. Eventually the charge leaks and loses stored data. Thus, it has to refresh every time the electric charge is connected. It is here that RRAM differs in its working. RRAM changes the resistance of the memory cell so that there is no loss of data or leaking of charge. This is done using memristors (a portmanteau of “memory resistor”), which have been there for a while but not potentially used. The concept of Memristor was first envisioned by a circuit theorist, Leon Chua.

FEATURES OF RRAM

RRAM would be a simple chip about the size of a postage stamp which can have the storage of about 1 terabyte. This simply unites the RAM, Hard disks in PCs and Laptops, and the Flash storage in the case of smart phones and tablets. It has a write speed of 10 nanoseconds and a read-write endurance of about one million cycle times, which is 10 times more than that of a normal flash drive.

THE FUTURE OF RRAM

It would be a step further to RAM. It can be used not only to run applications, but can also be used as a secondary storage device. If it is used in smart phones and tablets, it will change the way applications are run. A company named Crossbar™ is working on a RRAM which may be used in Coffee makers and car dashboards. The researchers have also found a method which involves less production cost and power consumption which will make RRAM more affordable.

So let us look forward, in our near future, to some “Super-Smart” gadgets built using this most innovative technology.

Akshay Ramnath

Akshay is a budding writer and a cricket enthusiast. He writes to improve his knowledge as well as the readers’. He is interested in technology and updates himself about it.

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