04-04-2013, 04:55 PM
Magnetoresistive Random Access Memory
[attachment=52863]
What is Magnetic RAM?
MRAM is memory technology that uses electron spin to store information
Unlike conventional RAM chip technologies, data is not stored as electric charge or current flows, but by magnetic storage elements.
What is Magnetic RAM? How does it work?
An MRAM chip is made up of millions of pairs of tiny ferromagnetic plates (like the one covering hard drives) called memory cells, i.e., magnetic sandwiches consisting of two magnetic layers separated by a very thin insulating layer
One of the two plates is a permanent magnet set to a particular polarity, the other's field will change to match that of an external field. A memory device is built from a grid of such "cells".
How does it work?
MRAM works like the read/write head of a hard drive.
But unlike a hard drive, which includes mechanical parts (the moving arm holding the read/write head and the rotating plates on which the information is stored), MRAM is a solid state device and, as such, has much greater speed and durability
How does it Read?
An MRAM chip reads information by measuring the electrical resistance of a specific cell that, in turn, depends upon the alignment of the magnetic moments of the layers of the cell.
To read a bit of information, a current is passed through the memory cell.
If the magnetic moments are in a parallel orientation, then the detected resistance would be smaller than if they were in an anti-parallel orientation.
How does it Write?
Write is achieved by the alignment of the magnetic moments of the two memory layers into one or the other relative orientation.
Current is passed through two sets of parallel wires or write lines (called a bit line and a digit or word line), which pass over and beneath the memory cells, respectively
To write to a particular memory cell (bit), current is passed through the two wires that intersect at that memory cell.
Advantages of MRAM
MRAM can resist high radiation, and can operate in extreme temperature conditions. It is likely that we’ll see the first MRAM in applications that need such properties
Like Flash, MRAM retains data after a power supply is cut off, potentially eliminating that seemingly endless boot time of conventional computers when data from the hard drive is transferred to RAM, as well as loss of data when the computer is suddenly shut off.
[attachment=52863]
What is Magnetic RAM?
MRAM is memory technology that uses electron spin to store information
Unlike conventional RAM chip technologies, data is not stored as electric charge or current flows, but by magnetic storage elements.
What is Magnetic RAM? How does it work?
An MRAM chip is made up of millions of pairs of tiny ferromagnetic plates (like the one covering hard drives) called memory cells, i.e., magnetic sandwiches consisting of two magnetic layers separated by a very thin insulating layer
One of the two plates is a permanent magnet set to a particular polarity, the other's field will change to match that of an external field. A memory device is built from a grid of such "cells".
How does it work?
MRAM works like the read/write head of a hard drive.
But unlike a hard drive, which includes mechanical parts (the moving arm holding the read/write head and the rotating plates on which the information is stored), MRAM is a solid state device and, as such, has much greater speed and durability
How does it Read?
An MRAM chip reads information by measuring the electrical resistance of a specific cell that, in turn, depends upon the alignment of the magnetic moments of the layers of the cell.
To read a bit of information, a current is passed through the memory cell.
If the magnetic moments are in a parallel orientation, then the detected resistance would be smaller than if they were in an anti-parallel orientation.
How does it Write?
Write is achieved by the alignment of the magnetic moments of the two memory layers into one or the other relative orientation.
Current is passed through two sets of parallel wires or write lines (called a bit line and a digit or word line), which pass over and beneath the memory cells, respectively
To write to a particular memory cell (bit), current is passed through the two wires that intersect at that memory cell.
Advantages of MRAM
MRAM can resist high radiation, and can operate in extreme temperature conditions. It is likely that we’ll see the first MRAM in applications that need such properties
Like Flash, MRAM retains data after a power supply is cut off, potentially eliminating that seemingly endless boot time of conventional computers when data from the hard drive is transferred to RAM, as well as loss of data when the computer is suddenly shut off.