DEBUGGING EMBEDDED SYSTEMS CAM REPRESENT MORE THAN HALF OF AN EMBEDDED-SOFTWARE-PROJECT WORKLOAD. UNDERSTANDING HARDWARE-DEBUGGING FUNCTIONS AND THE ISSUES THEY TACKLE IS KEY TO SELECTING THE RIGHT CHIPS, BUILDING DEBUGGING SYSTEMS, AND INCREASING PRODUCTIVITY. Many people erroneously credit the term "bug" to Rear Admiral Grace Murray Hopper. In fact, however, no one knows where the term originated, and it may go back to Thomas A Edison or even earlier. Nevertheless, US Naval Reservist Hopper found a moth that had short-circuited Relay #70, Panel F, of the Mark II Aiken Relay Calculator while it was being tested at Harvard University on Sept 9,1945. By removing the moth - that is, "debugging" the computer, she solved the glitch that had temporarily shut down the machine (Reference 1). Although that early example literally removed a bug from a system's hardware, "debugging" today refers to the process of understanding a program failure and removing the defective code. A failure includes any small deviation from the original intention, and removing the defective code is much better than adding correction code. In an ideal situation, all characteristics, such as bus and register values of a system, would be accessible at any time for monitoring and modification. But with ICs moving toward SOCs (systems on chips), accessibility becomes more difficult.
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机译：嵌入嵌入式系统的CAM的数量比嵌入式软件工作量的一半还多。了解硬件调试功能及其问题是选择正确芯片，构建调试系统并提高生产率的关键。许多人错误地将“臭虫”一词归功于海军少将格蕾丝·默里·霍珀。但是，实际上，没有人知道这个词的起源，它可能会追溯到Thomas A Edison甚至更早的时期。尽管如此，美国海军预备役军人霍珀在1945年9月9日在哈佛大学进行测试时，发现一种蛾子使Mark II Aiken中继计算器的＃70继电器F面板短路。通过消除飞蛾-即“调试”计算机，她解决了暂时关闭计算机的故障（参考文献1）。尽管该早期示例从字面上消除了系统硬件中的错误，但如今的“调试”是指理解程序故障并删除有缺陷的代码的过程。故障包括与原始意图的任何微小偏差，并且删除有缺陷的代码比添加纠正代码要好得多。在理想情况下，可以随时访问所有特性，例如系统的总线和寄存器值，以进行监视和修改。但是随着IC向SOC（片上系统）发展，可访问性变得更加困难。
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