Q&A watchdog is the most complex watchdog scheme that can be implemented with the TCAN28XX line of devices. This integrates the window period of the window watchdog, but increases the complexity of the response trigger. In Q&A mode the watchdog has a window setup like in window watchdog, but the SBC expects responses in both sections of the total window. In this setting the SBC can pose a question that is read by the controller and the controller can respond with a 4-byte answer. The initial question read and the thee most significant bytes send to the SBC must occur in the first window section where the least significant byte is transmitted during the second period. Upon the reception of the last answer byte the question is reset, so in the first window the controller can actually skip the question request and just start with the answer (as long as the new question is known by controller). This not only makes sure that the communication link is in a decent condition like the previous watchdog types, but this also adds a layer of complexity by making the controller solve math problems and respond in reasonable state of time. This makes sure that valid data is being sent by the controller, not just if the controller is responding or not which gives an additional layer of robustness in the system as certain issues are not caught by standard watchdog implementations.