FAULT TOLERANT CMOS REALIZATION OF A MINORITY FUNCTION FOR AEROSPACE COMPUTER COMPLEXES
In recent years, increased attention is paid to the reliability of the critical applications of digital equipment. Reliability means radiation resistance of digital equipment. For aerospace computer systems it is extremely urgent to develop radiation-resistant components. It is one way to ensure that the radiation resistance is the creation of a special archi- tecture - RHBD (Radiation Hardened by Design). This approach includes triple redundancy (Triple Modular Redun- dancy, TMR). In implementing the triple redundancy to increase radiation resistance in the Xilinx FPGA Virtex used majoritarian elements based on a tristate buffer. One of the issuance of majority vote circuit for the loading sign to the pins of the FPGA is using a minority voting function. This feature ensures channel disconnection different from the other two. Only in this case, there is no conflict of signals at the outputs of buffers. Then it was realized majority func- tion (voting by a majority). The FPGA logic elements LUT (Look Up Table) werer used for it. However, in this case FPGA logic resources were spent. CMOS implementation element vote on the minority was described. The paper proposes a fault tolerant CMOS implementation of minority voting function as separate elements in order to improve the performance of redundant circuits and do not use FPGA logic resources. Simulation of CMOS voting member in the minority is made in the circuit simulation of National Instruments Electronics Workbench Group system. Simulation confirms efficiency of the proposed element, and evaluation of the probability of failure-free operation shows its high efficiency. Winning there is a considerable range of probabilities as opposed to triple scheme that gets worse unre- served already at the probability of the order of 0.88.