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.
Filter drivers are optional drivers that add value to or modify the behavior of a device. A filter driver can service one or more devices. Bus Filter Drivers. Bus filter drivers typically add value to a bus and are supplied by Microsoft or a system OEM (see the Possible Driver Layers figure). Bus filter drivers are optional. There can be any number of bus filter drivers for a bus. A bus filter driver could, for example, implement proprietary enhancements to standard bus hardware. For devices described by an ACPI BIOS, the power manager inserts a Microsoft-supplied ACPI filter (bus filter driver) above the bus driver for each such device.