3.4 - High Resolution Diagnostic Techniques for the IBM S/390 Microprocessor Authors: Peilin Song, Franco Motika, Mary Kusko, Rick Rizzolo, Julie Lee and Robert Clairmont Univ/Comp: IBM Presenter: Peilin Song - psong@us.ibm.com ******** Abstract: Understanding the root causes of chip failure is the key to improving yield and reliability. To ensure rapid improvements, quick turn around time and high success rate through the diagnostic/physical failure analysis (PFA) path is necessary. This paper describes how tester-based diagnostic techniques combined with circuit fault simulation techniques were used in the hardware bring-up of the IBM S/390 G5 CMOS microprocessor and the associated cache chips.