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.
PCI is an abbreviation for Peripheral Component Interconnect, which is a term used to describe a common connection interface for attaching computer peripherals to a PC's motherboard, or main circuit board. It is also called a PCI bus. A bus is a term for a path between the components of a computer. Most often, a PCI slot was used to connect sound and network cards. PCI at one time was used to connect video cards, but graphics demand from gaming made it inadequate for that use.