1. Roadmap History Synchronized vs. Asynchronous overview How it works
Benefits of clockless chips
Limitations of clockless chips
Potential for the future

2. How fast is your computer?
Speed of clock
Billionth of a second long
All operations governed by speed of clock
Many operations take different speeds
Must be coordinated

3. History Asynchronous design considered in 1946 by Alan M. Turing
David A. Huffman and David E. Muller
ILLIAC II (1962)
Was not reliable with technology of the time
Vacuum tubes and relay circuits
Moore's law

4. Disadvantages of clock
Process of diminishing returns
Slowest process governs speed
Clock runs during idle time
Increased power consumption
Speed of light

5. Asynchronous Processor
Event driven
System of local handshaking
No global clock
Needs way govern processes
Signals indicate completion
Employes Rendezvous and Arbiter gates

6. Asynchronous Processor (cont.)
State of circuit changes instantly with signal
Varying speed patterns results in varying electromagnetic waves
Design must account for speed patterns

7. Asynchronous Processor (cont.)
Without clock, must know when operation is done
Dual-rail circuits
Yes, no, or no answer yet

8. Delay-Intensive Model
Makes no assumptions
All transistors must be acknowledged

9. Principle of their advantages
Variable length processes
division

10. Do they exist? ARM Holdings and Handshake Solutions Philips
ARM996HS
Proposed for use in automotive/medical equipment
Philips
Pagers
Intel, IBM, Sun

11. Benefits of Clockless chips
Executing of individual functions does not wait for next clock pulse
Up to 3 times faster
Less power consumption
Idle time
Lower electromagnetic pulse

12. Limitations Lack of automated designing/testing tools
Strict attention to physical design
Lengths of wires, logical gates
Predicting complex sequences and coordinating

13. Inhibitors of Development
Pace of market competition
Education
Synchronous easier to test

14. Conclusion Many advantages over synchronous
Handshakes and coordination circuits
Implementation lengthy, lack of resources
Physical limitations of clock

15. References
pdfs/Pgs20-24_IQ17.pdf
story/401226/its-time-for-clockless-chips/2/
s/552/coursematerials/ee552-H5.pdf
qM&feature=related
products/processors/ /ARM-offers- first-clockless-processor-core
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