** on request it can be provided as bidirectional open-drain pinwith internal 10kOhm pull-up to 3.3V. In this case, beside the output function described previously, it allows carrier board logic to inhibit NAND flash write operations directly. For example system integrator could imagine a scenario where a hardware watchdog - that monitors host processor connected to DUL - acts on this pin by disabling write operations in case processor hangs. This option is extremely powerful but it must be handled with care. In case carrier board logic pulls EXT_FWP# down, NAND controller is not able to detect this condition thus it continues to report to the host that the media is writable. This may lead to unpredictable behaviour, depending on several factors, including operating system - if any - running on host machine.