An outstanding feature on the SAM3U4 is the dual-boot Flash bank selection capability for IAP. This is managed by one of the GPNVM bits. GPNVM bits 0 and 1 have the same functionality as on the SAM7 products, but the GPNVM bit 2 is specific to the SAM3U. This bit is responsible for the Flash selection, either Flash 0 or Flash 1. There are two Flash banks available, Flash bank 0 at the address 80000 and Flash bank 1 at address 100000. The user may have two different applications. When the GPNVM bit 2 is cleared, boot will occur at Application 1, and the Application 1 will be seen at Address 0. If the GPNVM bit 2 is set, then boot will occur at Application 2, or the Flash Bank 1 seen at Address 1. This is particularly useful when the customer wants to perform In-Application Programming.