Graham Hetherington

Logic BIST for large industrial designs: real issues and case studies

This paper discusses practical issues involved in applying logic built-in self-test (BIST) to four large industrial designs. These multi-clock designs, ranging in size from 200 K to 800 K gates, pose significant challenges to logic BIST methodology, flow, and tools. The paper presents the process of generating a BIST-compliant core along with the logic BIST controller for at-speed testing. Comparative data on fault grades and area overhead between automatic test pattern generation (ATPG) and logic BIST are reported. The experimental results demonstrate that with automation of the proposed solutions, logic BIST can achieve test quality approaching that of ATPG with minimal area overhead and few changes to the design flow.

Minimizing power consumption in scan testing: pattern generation and DFT techniques

It is a well-known phenomenon that test power consumption may exceed that of functional operation. ICs have been observed to fail at specified minimum operating voltages during structured at-speed testing while passing all other forms of test. Methods exist to reduce power without dramatically increasing pattern volume for a given coverage. We present case study information on ATPG- and DFT-based solutions for test power reduction.

Testing high-speed, large scale implementation of SerDes I/Os on chips used in throughput computing systems

Throughput computing requires chip I/O bandwidth of the order of Tbits/sec which can be met by high speed, large scale implementation of SerDes I/Os (serial/deserial differential I/Os with clock embedded in data stream). The traditional test philosophy and existing ATE do not meet the challenges of testing chip interfaces with few hundreds of I/Os operating at multi-Gbps. In this paper, we present the test challenges and describe on-chip DFT modes and new ATE directions for chip level characterization and test of such interfaces used in throughput computing chip sets

Circular bist testing the digital logic within a high speed serdes

High Speed Serializer Deserializers (serdes) are traditionally tested using functional BIST. This paper presents an improved BlST for testing the digital part of a serdes using circular BET.

Test generation and design for test for a large multiprocessing DSP

The TMS320C80 is a programmable, parallel processing DSP. The test approach was an engineering mix of design for testability, test view creation, and verification. This mixture facilitated timely test generation and had other important benefits. We document the overall test methodology and the benefits derived therein.

A holistic parallel and hierarchical approach towards design-for-test

While design-for-test methods such as scan, ATPG, and memory BIST are now well established for ASIC products, their run-time for multi-million gate designs has become a problem. Too often, a tape-out is held up because pattern generation and verification are incomplete. This work describes a holistic design-for-test approach which exploits both hierarchy and parallelism on every aspect of the DFT to minimize the run-time impact.