LBIST/ATPG Technologies for On-Demand Digital Logic Testing in Automotive Circuits

Abstract

With a large focus on test data size and fitting into tester's capabilities, sometimes the focus of field testing is pushed to the side. There is an emerging market in automotive design where greater emphasis is being placed on the need for field testing of the digital logic. Tried and true mechanical systems are being replaced by digitally controlled logic. This path is being pursued by automotive manufactures with an effort for higher fuel economy, lighter designs, and more integrated user experiences. These systems require high dependability throughout the life of the automobile. Defects caused by heat, environmental exposure and time can jeopardize critical digital system from performing as designed. Identifying these defects before critical failure is a paramount concern to automotive manufactures. A major automotive chip manufacturer and Cadence's Encounter Test's DFT and ATPG system have worked together to insert an efficient direct access LBIST into its automotive design requiring high reliability for the lifetime of the product. The LBIST provides a means to test the digital logic and provide a go/no-go signal to identify that the logic still performs as originally manufactured. Purchaser of these chips required a technology to provide 96%+ static coverage using on-chip testing that can be run at system power up or at any time. This poster presents a summary of how Cadence's Test technologies were used to meet customer needs and summarizes the overall test flow and experience.