Abstract

The paper introduces a new approach for designing of self-checking Microprogram Control Units (MCU). Using a Finite State Machine (FSM) as a form of MCU representation leads to its PLA-implementation having a system of product terms which are orthogonal and complete. An additional important property of MCU is related to a limited total number of possible code-words. These features can be used for construction of self-checking PLAs with relatively small overheads. Keywords: Self-checking, on-line checking, microprogram control unit. 1. Output vectors of fault-free devices are always code-words of a specific code, and error detection is implemented by checking whether the present output belongs to the code. Major difficulties in design of self-checking devices are related to complexity of decoding (which is verification that a given output is a code-word). An objective of the paper is to derive a ne