Editing Central processing unit (section)

===Clockless CPUs===
Another method of addressing some of the problems with a global clock signal is the removal of the clock signal altogether. While removing the global clock signal makes the design process considerably more complex in many ways, asynchronous (or clockless) designs carry marked advantages in power consumption and [[heat dissipation]] in comparison with similar synchronous designs. While somewhat uncommon, entire [[Asynchronous circuit#Asynchronous CPU|asynchronous CPUs]] have been built without using a global clock signal. Two notable examples of this are the [[ARM architecture family|ARM]] compliant [[AMULET microprocessor|AMULET]] and the [[MIPS architecture|MIPS]] R3000 compatible MiniMIPS.<ref name=":2">{{Cite journal |last1=Martin |first1=A. J. |last2=Nystrom |first2=M. |last3=Wong |first3=C. G. |date=November 2003 |title=Three generations of asynchronous microprocessors |url=https://ieeexplore.ieee.org/document/1246159 |url-status=live |journal=IEEE Design & Test of Computers |volume=20 |issue=6 |pages=9–17 |doi=10.1109/MDT.2003.1246159 |issn=0740-7475 |s2cid=15164301 |archive-url=https://web.archive.org/web/20211203174748/https://ieeexplore.ieee.org/document/1246159/ |archive-date=2021-12-03 |access-date=2022-01-05|url-access=subscription }}</ref>

Rather than totally removing the clock signal, some CPU designs allow certain portions of the device to be asynchronous, such as using asynchronous [[Arithmetic logic unit|ALUs]] in conjunction with superscalar pipelining to achieve some arithmetic performance gains. While it is not altogether clear whether totally asynchronous designs can perform at a comparable or better level than their synchronous counterparts, it is evident that they do at least excel in simpler math operations. This, combined with their excellent power consumption and heat dissipation properties, makes them very suitable for [[embedded computer]]s.<ref>{{cite conference |author1=Garside, J. D. |author2=Furber, S. B. |author3= Chung, S-H | title = AMULET3 Revealed | publisher = [[University of Manchester]] Computer Science Department | year = 1999 | url = http://www.cs.manchester.ac.uk/apt/publications/papers/async99_A3.php |book-title=Proceedings, Fifth International Symposium on Advanced Research in Asynchronous Circuits and Systems |doi=10.1109/ASYNC.1999.761522 | archive-url=https://web.archive.org/web/20051210205845/http://www.cs.manchester.ac.uk/apt/publications/papers/async99_A3.php | archive-date=December 10, 2005 | url-status=dead| url-access=subscription }}</ref>