Digital Comparator in Excitable Chemical Media
Shan Guo, Ming-Zhu Sun, Jian-Da Han and Xin Zhao
It is well established that spatial excitable media can be used for information processing. A single excitation pulse can represent one bit of information and a group of excitations forms a message. Different structures designed can realize different functions of information processing. In this paper, we systematically designed structures of digital comparator, and numerical simulations have been carried out to show that these structures can realize the function of digital comparator well. Firstly we designed one-bit and two-bit digital comparator, and then we successfully designed three-bit digital comparator in two different ways, thus we demonstrated two expanding ways to realize the multi-bit digital comparator: nesting way and cascading way. We believe that the realization of digital comparator is helpful for the constructions of other logic and arithmetic functions, and ultimately can bring great potential applications for the implementation of chemical computer and other intelligent systems.
Keywords: Chemical computation, Belousov-Zhabotinsky reaction, excitable media, logic circuits, digital comparator, nesting way, cascading way