Boundary-Scan, formally known as IEEE/ANSI Standard1149.1-1990, is a collection of design rules applied principally atthe Integrated Circuit (IC) level that allow software to alleviate thegrowing cost of designing, producing and testing digital systems. Afundamental benefit of the standard is its ability to transformextremely difficult printed circuit board testing problems that couldonly be attacked with Ad-Hoc testing methods into well-structuredproblems that software can easily and swiftly solve. IEEE testing standards of the 1149 family are living entities thatgrow and change quickly. The Boundary-Scan Handbook, Third Edition isintended to describe these standards in simple English, rather thanthe strict and pedantic legalese encountered in the standards. Over180 drawings and 40 tables illustrate important concepts. Forty-sixDesign-for-Test rules are provided, with complete explanations. The fundamental 1149.1 standard is now over 13 years old and has alarge infrastructure of support in the electronics industry. Today, amajority of custom ICs and Programmable Logic Devices have 1149.1implementations. The Boundary-Scan Handbook, Third Editionupdates the information about 1149.1, which has been revised asrecently as 2001. It contains a description of the 1149.4 AnalogBoundary-Scan standard, and gives a tutorial on analog testingtechnology. It then introduces the recently released IEEE 1149.6Advanced I/O standard, which extends Boundary-Scan to deal withAC-coupled differential signaling now becoming common in higherperformance system. Finally, since a board test system provides asuitable environment for programming non-volatile Programmable LogicDevices, the IEEE 1532 standard is described which extends the 1149.1access protocol into the device programming domain. This forms anessential tools for testing boards and systems of the future.