A 16-Mbits Atmel Serial Dataflash (AT45D161D) is connected to the ATmega3290P's Serial Peripheral Interface (SPI). This storage is used for safe firmware images, sounds and general-purpose parameters. See the firmware documentation for an overview of occupied sectors, and those available to the end user. Even with a couple of safe firmware images for the two microcontrollers there is plenty space left for the end user. Note that the serial Dataflash will operate properly when the voltage is above 2.5 Volts while the rest of the design will operate down to 1.8Volts