This paper discusses an online testing strategy based on BIST approaches where a novel optical built-in logic-block observation (OBILBO) register was proposed. The OBILBO is similar to the conventional one in addition to optical probing capability since novel optical probes (OPs) are considered in its architecture. Preliminary simulation results show that, for duplex system cases, fault detection of the normal function of the system is carried out concurrently. In other words, we should emphasize that no tests are applied. Therefore, there is no need to stop the current application.
This is achieved through the exploitation of optical beams produced by the OBILBO according to the captured data present at the outputs of the OBILBO and then sent to a remote system equipped with optical sensors such as a PIN diode. Thus, a comparison is possible in real-time. Furthermore, the proposed approach can also be used in the offline mode by selecting the MISR mode of the OBILBO and analyzing the signature in the remote system. Compared to the previous research work, the proposed solution handles the problem of observing test results more efficiently since novel OPs are considered. So, the proposed scheme has very low error detection latency at the expense of extra hardware. In future research work, a complete investigation of the benefits and drawbacks of the optics-based testing approach will be considered.