LPC ARM microcontrollers with the SPIFI interface have two options for booting with the external SPI Flash. First, a user may set certain external pins low, which tell the MCU during start-up to look for external SPI Flash connected to SPIFI. However, if a customer wants to use those boot pins for other functions, there is an option to set a Flash bit to override the pin setting. This will free up the pins and allow the user to not worry about the dual functionality of the pins.