Computers as Components, 3rd Edition

6.3 Multirate Systems

Implementing code that satisfies timing requirements is even more complex when multiple rates of computation must be handled. Multirate embedded computing systems are very common, including automobile engines, printers, and cell phones. In all these systems, certain operations must be executed periodically, and each operation is executed at its own rate.

Application Example 6.1 describes why automobile engines require multirate control.

Application Example 6.1 Automotive Engine Control

The simplest automotive engine controllers, such as the ignition controller for a basic motorcycle engine, perform only one task—timing the firing of the spark plug, which takes the place of a mechanical distributor. The spark plug must be ...