UDC 681.32
FEATURES OF THE TRUTH TABLE INVERSION IN THE FAULT TOLERANT FINITE STATE MACHINE SYNTHESIS
S. F. Tyurin, Honored Inventor of the Russian Federation, PhD (technical sciences), Professor at the Department of Automation and Telemechanics, Perm National Research Polytechnic University; This email address is being protected from spambots. You need JavaScript enabled to view it..
Fault-tolerant finite state machines may be built on the basis of special reliable logic elements. One way to improve reliability is to introduce redundancy elements. Basis 2OR-2AND-NOT implemented in CMOS transistor chain comprises two series-connected transistors, which enables to perform transistor redundancy, where the chain will include four serially connected transistors. This is the maximum value according to the limitations of Mead and Conway. In contrast to bases 2AND-NOT, 2 OR-NOT also allows such reservation, 2OR-2AND-NOT due to its duality provides a simpler scheme in most cases. In the synthesis of the elements in this basis by the truth table in DNF it is necessary to divide it into two parts, with the inversion of received sub-tables. In sub-tables inversion using De Morgan's law, which leads to the inversion procedure of each line, followed by the Cartesian product of the sets obtained. There are features of negation table with orthogonal variable-that is, in one sub-table of the table variable is meaningful, for example, zero, and the other sub-table – one. The use of such tables inversion allows to simplify general inversion algorithm and reduce the complexity of combinatorial synthesis. It stands out as a table, in which all rows are mutually orthogonal. The aim of the work: to determine the negation table features with mutually orthogonal lines. It is shown that the rule of negation table from two rows with an orthogonal variable can be extended in the event of denial of orthogonal vectors.
Key words: truth table, disjunctive normal form, inversion