Patent ID: 7065751

Claim:
A program execution device of executing a program described in a non-native code format of a prescribed language, comprising: a compressed code storing portion storing a code of said program compressed on a prescribed unit basis; an expanding portion connected to said compressed code storing portion for expanding said compressed code stored in said compressed code storing portion; a code storing portion connected to said expanding portion for storing the code expanded by said expanding portion; and an interpreter portion connected to said code storing portion for interpreting said expanded code for execution in said non-native code format, wherein said expanding portion expands a first compressed code stored in said compressed code storing portion, stores a first expanded code in said code storing portion and holds said first compressed code in said compressed code storing portion, after said interpreter portion interprets said first expanded code for execution, said expanding portion expands a second compressed code stored in said compressed code storing portion, overwrites a second expanded code on said first expanded code in said code storing portion and holds said second compressed code in said compressed code storing portion, and after said interpreter portion interprets said second expanded code for execution, said expanding portion expands said first compressed code stored in said compressed code storing portion and overwrites said first expanded code on said second expanded code in said code storing portion.