12.7 Processor Problems

12.7.1 Overview

This section is primarily concerned with processor-related runtime problems. It deals with issues resulting from either CPU register or memory malfunctions. Such malfunctions may be induced in a number of ways: electrical noise, aberrant program behavior, excessive temperatures, hardware faults, and more. The techniques used to seek to answer three questions:

1. Is it OK to use the processor system in the first place?
2. Is it safe to continue using the processor system in its normal running mode?
3. If problems are detected, can we recover from the situation?

Questions (2) and (3) are closely interlinked and will be dealt with together as appropriate.

It is important to understand that these tests are not foolproof. Therefore, they augment, not replace, hardware-based techniques (for example, watchdogs and memory management units). Their advantages, when they work, are that they can do the following:

• Warn us of processor...