1 Each term should be used in one and only one way throughout the dissertation.  The easiest way to avoid a long series of definitions is to include a statement: ``the terminology used throughout this document follows that given in [CITATION].'' Then, only define exceptions.
Serial Peripheral Interface Bus. The Serial Peripheral Interface bus (SPI) is a synchronous serial communication interface specification used for short distance communication, primarily in embedded systems. The interface was developed by Motorola in the late 1980s and has become a de facto standard. Typical applications include Secure Digital cards and liquid crystal displays.
A data bus is a computer subsystem that allows for the transferring of data from one component to another on a motherboard or system board, or between two computers. This can include transferring data to and from the memory, or from the central processing unit (CPU) to other components. Each one is designed to handle so many bits of data at a time.