MICROPROCESSOR DEVICE

PROBLEM TO BE SOLVED: To provide a microprocessor device which reduces the capacity of a sub instruction memory inside the processor and also reduces a data transfer load to the outside.SOLUTION: A microprocessor device includes: a main instruction memory unit for storing an instruction code; a sub instruction memory unit for storing a part of the instruction code; a instruction code processing unit for reading the instruction code from the sub instruction memory unit for execution; a instruction set reading unit for reading an instruction set from the main instruction memory unit to the sub instruction memory unit. When the instruction code processing unit detects a sub instruction set load instruction, the instruction set reading unit reads the instruction set of the main instruction memory unit according to the reading area information of the instruction set of the main instruction memory unit included in the sub instruction set load instruction and writes the read instruction set into the sub instruction memory unit according to the writing area information of the instruction set of the sub instruction memory unit included in the sub instruction set load instruction.