1. Select Debug | Prepare to Attach.
2. If using Hot Attach, follow the Hot Attach procedure to safely attach to the Target.
3. Select Hardware | Scripts | Unsecure (can also be Chip Erase or similar).
This operation needs JTAG/SWD debug port to be accessible. Devices, where the debug port, is deactivated when secured, cannot be recovered this way. Only available in winIDEA on selected devices: EFM32, Kinetis, Atmel, S32K, LPC546xx, nRF52.
This is a special command for Cortex-M that uses available low-level debug functionality in the target CPU to remove the protection programmed into internal Flash. This operation erases internal memory and therefore prevents protected code from being read by a third party. Unsecure enables you to regain use of the chip which might get secured unintentionally during application development.