8.1 Introduction

Many embedded computing systems require more than one CPU. To build such systems, we need to use networks to connect the processors, memory, and devices. We must then program the system to take advantage of the parallelism inherent in multiprocessing and account for the communication delays incurred by networks. This chapter introduces some basic concepts in parallel and distributed embedded computing systems. Section 8.2 outlines the case for using networks and multiprocessors in embedded systems. Section 8.3 explores the multiprocessor design space and the major categories of multiprocessors. Section 8.4 looks at distributed systems, using several example networks. Section 8.5 considers shared-memory multiprocessors. Section 8.6 walks through the design of a video accelerator as an example of a specialized processing element. Section 8.7 looks at compact disc players as an example of heterogeneous multiprocessors.