Introduction

Memory Built-In Self-Test (MBIST) has become an essential technique for ensuring the reliability of embedded memory systems in ASICs and SoCs. Traditionally, MBIST is used during manufacturing testing to identify faults in memory cells, but online diagnostics takes it a step further by enabling real-time fault detection during operation. This can be particularly valuable for mission-critical applications that require continuous monitoring, such as automotive or industrial systems.

However, implementing MBIST for online diagnostics presents several challenges that need to be overcome to ensure efficient operation and accurate fault detection.

Problem Statement

When MBIST is applied for online diagnostics, some of the major challenges which must be addressed are mentioned below

1. Seamless MBIST Insertion for Online Operation

• Integrating MBIST into the design for real-time operation without disrupting the chip’s performance can be challenging.
• The MBIST controller must be able to run diagnostics concurrently with the normal operation of the system, without adding excessive overhead.

2. Adaptive Test Pattern Generation for Real-Time Fault Detection

• Test patterns used for online diagnostics must be adaptive to detect faults as they occur during the chip’s operational life.
• Ensuring that these patterns do not interfere with normal device functionality or cause excessive power consumption is a major concern.

3. Real-Time Fault Detection and Reporting

• The MBIST controller needs to continuously monitor and identify faults in memory while the system is running, generating accurate diagnostic reports.
• Ensuring timely and accurate fault detection is critical for preventing system failures

4. Efficient Fault Diagnosis and Correction

• Once a fault is detected, isolating and diagnosing the fault quickly is essential for minimizing system downtime.
• Incorporating repair mechanisms such as redundancy or sparing can improve system reliability.

Conclusion

MBIST for online diagnostics introduces new challenges in terms of real-time operation, fault detection, and reporting. A successful implementation requires efficient integration, adaptive testing, and reliable fault diagnosis and correction

At AiSemi Private Limited, we specialize in providing customized MBIST solutions tailored to your design needs. Contact us to learn how we can help enhance your chip testing process and ensure first-time silicon success.