# Development of a Non-Invasive On-Chip Interconnect Health Sensing Method Based on Bit Error Rates
## 5 Conclusions  
In this paper, we presented an on-chip health sensing method for non-invasive and non-destructive interconnect degradation monitoring. Digital signals were transmitted and received through an interconnect of interest. Using SI analyses, it was demonstrated that the BER matrix can be used to detect interconnect faults without requiring additional sensing devices, as early as DC resistance did under accelerated life testing. The eye size of the BER matrix showed the highest separation between normal and abnormal states, indicating its potential for serving as an interconnect health indicator.  
These experimental results imply that interconnect fault sensing can be performed without requiring additional sensing devices, and thus, without interrupting system operation. Thus, the use of this on-chip health sensing method for critical interconnects or components should allow for electronics-based system health monitoring in real time and avoiding failure by providing early  
Figure 14: BER matrix during the test times (Test #1) of (**a**) 37, (**b**) 850, (**c**) 1684, (**d**) 1713, (**e**) 1745, and (**f**) 1766 min.  
warnings of impending failure. These warnings can provide a basis for system diagnosis and prognosis, and, in turn, effective system health management.  
The proposed on-chip health sensing method can eventually substitute current DC resistance-based health sensing by embedding it into electronics-based systems. No requirement of external and additional sensing devices should allow users to have real-time access to system health status, providing users with opportunity for system diagnosis and prognosis for proactive asset management. This data-based decision-making practice should be able to reduce potential system reliability concern, increasing system availability.  
However, the proposed on-chip health sensing method has limitations in terms of measurement methodology and conditions. Because the proposed method measures the BER using digital signals, the components of interest should be in operation and transmitting digital signals. Moreover, a dedicated sensing circuitry, including a transmitter and receiver, would be needed within the electrical circuit to construct a signal transmission channel. Thus, failure modes, mechanisms, and effect analysis (FMMEA) would be helpful to prioritize the components to be monitored when implementing our proposed method.  
Our future work on this subject will involve additional acceleration testing under different stress conditions, use of combined features, and statistical anomaly detection techniques for automatic fault diagnosis, such as sequential probability ratio test (SPRT) and statistical process control (SPC) charts.  
Project administration, D.K.; Writing--original draft, I.S.; Writing--review & editing, K.K. and D.K. This research was supported by Basic Science Re-search Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03028604), and by the Ulsan Metropolitan City (1.180032.01). The authors declare no conflicts of interest.