ABSTRACT
This chapter introduces the basic building blocks of the digital logic systems found in modern aircraft. It provides a brief overview of coding systems and the logic arrangements that are used to generate and convert the codes that are used to represent numerical data. The chapter also provides an introduction to aircraft bus systems. It deals with a brief overview of the architecture and principal constituents of simple computer systems. The chapter also deals with a review of the different types of logic gates before moving on to explore their use in several typical aircraft applications. Within the Line replaceable units (LRU), the dedicated digital logic and microprocessor systems that process data locally each make use of their own local bus system. Within the LRU data is transferred using an internal parallel data bus. ARINC 429 employs a unidirectional data bus standard known as Mark 33 Digital Information Transfer System.
