01-04-2010, 02:52 PM
WELCOME
OVONIC UNIFIEDMEMORY
ORGANISATION OF THE PRESENTATION
Introduction
Overview of present memories
Fundamentals of emerging memories
Ovonic Unified Memory
Memory Structure
VI Characteristics
Features of OUM
Circuit Demonstration
Advantages of OUM
Conclusion
OVERVIEW OF PRESENT MEMORIES
The current memory technology has a lot of limitations.
DRAM is difficult to integrate.
Flash has slower writes and lesser number of write/erase cycles compared to others.
Only two dimensional expansion is allowed, hence larger space required.
Also storage capacity is also limited.
FUNDAMENTALS OF EMERGING MEMORIES
FeRam
Polymer Memory
NROM
MRAMS
Ovonic Unified Memory
CHALCOGENIC MATERIAL
Chalcogenide is the general class of switching media in CD switching media in CD-RW and DVD RW and DVD-RW RW
“ In high volume production and low cost
Laser beam energy is used to control the
switching between crystalline and amorphous phases
“ Higher energy -> amorphous
“ Medium energy -> crystalline
Low energy laser beam to read
Amorphous vs crystalline surfaces
Ovonic Unified Memory(OUM)
Instead of using laser beam, use electric current to heat the material.
“ High current, high temperature: amorphous phase, high resistance
“ Medium current, lower temperature: crystalline phase, low resistance
Low current to sense resistance
MEMORY STRUCTURE
INTEGRATE WITH CMOS
V-I CHARACTERISTICS
GOAL OF THE INTEGRATION
To develop the processes necessary to connect the memory element to CMOS transistors and metal wiring, without degrading the operation of either the memory elements or the transistors.
maximize the potential memory density of the technology by placing the memory element directly above the transistors and below the first level of metal as shown in a simplified diagram
above.
BASIC DEVICE OPERATIONSet/Reset Pulses
FEATURES OF OUM
Non-volatile in nature
High density ensures large storage of data within a small area
Non destructive read:-ensures that the data is not corrupted during a read cycle.
Uses very low voltage and power from a single source.
Poly crystalline
This technology offers the potential of easy addition of non volatile memory to a standard CMOS process.
This is a highly scalable memory
Low cost implementation is expected.
CIRCUIT DEMOSTRATION
ADVANTAGES OF OUM
OUM uses a reversible structural phase change.
Small active storage medium.
Simple manufacturing process.
Low voltage single supply.
Reduced assembly and test costs.
Highly scalable- performance improves with scaling.
Multi states are demonstrated.
High temperature resistance.
Easy integration with CMOS.
It makes no effect on measured CMOS transistor parametric.
Total dose response of the base technology is not affected.
CONCLUSION
Optimized OUM can possess strong endurance, retention, and disturb capability.
OUM technology offers great potential for low power operation and radiation tolerance, which assures its compatibility in space applications.
All mechanisms depend on purity and compatibility of the chalcogenide and surrounding materials.
OUM offers a way to realize full system-on-a-chip capability through integrating unified memory, linear, and logic on the same silicon chip.
Detailed acceleration and atomic-level models are areas for future work.
REFERENCES
intel.com
ovonyx.com
baesystems.com
aero.org
IEEE SPECTRUM, March 2003
THANK YOU
please read http://studentbank.in/report-ovonic-unif...ull-report
http://studentbank.in/report-ovonic-unif...d-abstract and http://studentbank.in/report-seminars-re...ied-memory for getting technical report and presentation of Ovonic unified memory