The present invention provides a central processing unit-containing large-scale integration (hereinafter, referred to as a "CPU-containing LSI") in which software stored in an external memory is incorporated partially into a random access memory (hereinafter, referred to as "RAM") and thereby the capacity of the RAM to be used can be held down, and an optical disk device including the same. In the CPU-containing LSI, the RAM includes a software storage region where software read in from the external memory on a module-by-module basis is stored, and an entry table in which entries are stored, with the entries each containing at least information as to a location and a size of a module stored in the software storage region. The CPU refers to the entry table to decide the location where a module to be read in from the external memory to the software storage region is to be stored, according to an incorporation-location search program.