Patent ID: 7162622

Claim:
A microcomputer which operates under a condition of being built into an apparatus which is controlled thereby, the microcomputer having a CPU (Central Processing Unit), and a user ROM (Read-Only Memory) having stored therein a user program which is executed by said CPU and has been prepared by a user, wherein said microcomputer comprises a boot ROM having stored therein an initialization program which is accessed and executed by said CPU prior to executing said user program, immediately after said CPU has been released from a reset condition, said initialization program being executed by said CPU to perform initialization processing which is necessary for enabling said CPU to execute said user program; wherein data utilized by said CPU in executing said initialization program include set values which can be specified beforehand by a user; a memory region constituting a user setting region, into which said set values can be written by a user, is reserved within said user ROM; during execution of said initialization program stored in said boot ROM, said set values are read out from said user setting region, and by said CPU in executing said initialization processing; and said initialization program is configured to enable at least a part of said initialization processing executed by said CPU when executing said initialization program to be modified in accordance with selective omission of writing data into said user setting region.