On-line current testing for a microprocessor based application with an off-chip sensor

Abstract

This work presents a prototype architecture that provides on-line IDDQ measurement for a microprocessor-based system. It has been implemented using an IDDQ testable microprocessor (the Intel 386/sup TM/ EX embedded microprocessor) and an off-chip current sensor. Three current test activation modes are supported. A direct test mode through a sensor dedicated pin, a test mode where the microprocessor controls the off-chip sensor, and a P1149.1 driven test. Measurements and architecture operation are detailed.