Patent ID: 7096351
Filing Date: 2006-08-22
Classification: G06F

Abstract:
1. A single-chip microcomputer comprising: a non-volatile memory having a plurality of memory block pairs as a combination of a plurality of memory blocks each formed of a user region for storing a program code by a user and a region for storing a boot area designation flag indicating that a boot program to be executed first at the time of system booting is stored in said user region, in which the boot program is stored in a user region of a memory block of a specific pair of memory blocks at an initial state where no boot region switching processing is conducted, a region switching flag for indicating in which memory block pair the boot program is stored in the user region among said plurality of pairs of memory blocks, and a control element for, when designating other pair of memory blocks not designated as a boot region as a new boot region, storing a value obtained by subtracting a predetermined value from an initial value set at said boot area designation flag of the memory block of all said memory block pairs in the boot area designation flag of each memory block of said other memory block pair and at the time of booting the system, if the values of the boot area designation flags in the memory blocks of said other memory block pair are equal and not the initial value, determining that the boot program is stored in said other memory block pair to set said region switching flag.