chapter

12

All the Rules in One Story

“You know my method. It is founded upon the observation of trifles.”

—SHERLOCK HOLMES, THE BOSCOMBE VALLEY MYSTERY

War Story. Company T had a small device that sometimes refused to start up because a microprocessor couldn’t properly read from a battery-backed-up memory. Some units were worse than others, and a unit that failed one start-up could work the next time. This meant that the data in the memory was okay—the problem was reading it.

Engineer A attacked the problem and concluded that it was caused by data bus noise of some sort, since the memory was being read incorrectly. The system was a small circuit board containing memory and a battery-backup memory controller, which had been added to an existing ...

Get Debugging now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.