Built-in-self-test considerations in a high-performance, general-purpose processor

The intent of this paper is to describe the built-in-self-test (BIST) design and verification methodology followed for thermal conduction modules (TCMs) in the aircooled IBM Enterprise System/9000 Type 9121 processors. The ES/9121 processor utilizes a mixture of bipolar and CMOS circuitry. Each ES/9121 processor TCM can accommodate a maximum of 121 logic and memory chips. There are five distinct TCMs in the uniprocessor configuration and the testability results achieved using BIST will be presented in this paper. The resources required to support the BIST process will also be presented. Finally, improvements to the BIST methodology will be discussed.