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.
4 PCI Express bus card slots (from top to 2nd bottom: x4, x16, x1 and x16), compared to a 32-bit conventional PCI bus card slot (very bottom) In computer architecture, a bus (a contraction of the Latin omnibus) is a communication system that transfers data between components inside a computer, or between computers. This expression covers all related hardware components (wire, optical fiber, etc.) and software, including communication protocols.