Overview

Finite state machines are critical for realising the control and decision-making logic in digital systems.

Katz [159 ]

Having established our preferred motion estimation algorithm, the last section of this book considers how this algorithm can be implemented using semi-custom digital hardware. This chapter discusses, at a low level, the techniques we used to implement our prototype motion sensor. We make no claim that our approach is unique, optimal, or appropriate for all design work, but this approach is very straightforward and worked well for us: we hope that you will find it useful too. Assuming the reader is familiar with the basics of digital design, we introduce some concepts from FPGA (Field Programmable Gate Array) and VHDL (Very-High-Speed-Integrated-Circuit Hardware Description Language) technology. Our descriptions are brief and it would be useful to have a VHDL reference available as you work through this chapter, however, there is sufficient information here for you to understand our design and start on your own projects. In order to keep the discussion generic, we try not discuss specific tools or technologies since these change regularly and there are large difference between tools from different vendors ^[130]. It is inevitable, however, that there will be some bias towards the tools we are most familiar with Xilinx Foundation software, and Xilinx Virtex FPGAs. Any links or references to particular vendors in this section are for your reference only. They do not imply an endorsement of that vendor s products or services.