Design for Testability Guidelines

Two approaches to the problem of limited external board access—solutions at the layout
level to improve testability

http://www.teradyne.com/atd/resource/docs/general/Micro%20Access%20Technologies%20.pdf
http://www.home.agilent.com/agilent/product.jspx?nid=-33994.911254.00&lc=eng&cc=US