Patent ID: 8164490
Filing Date: 2012-04-24
Classification: H03M

Abstract:
1. A data compression method of generating compressed data by compressing compression target data including an instruction code, the method comprising: a repetition condition determination step of sequentially detecting repetitive portions in the compression target data, and determining whether an approximately corresponding position of the repetitive portion is under a first repetition condition, which is a position corresponding to a multiple of an instruction word length as a number of bytes expressing the instruction code, or a second repetition condition, which is not the first repetition condition; a first repetition code generation step of generating a first repetition code including at least a value specifying a compression—approximately corresponding position, obtained by dividing the approximately corresponding position that corresponds to the repetitive portion by the instruction word length and a value specifying a length of a corresponding portion at the approximately corresponding position in the repetitive portion, and of outputting the generated code as the compressed data, the generation and the outputting occurring when the repetitive portion is under the first repetition condition; a second repetition code generation step of generating a second repetition code including at least a value specifying the approximately corresponding position that corresponds to the repetitive portion and a value specifying a length of a corresponding portion at the approximately corresponding position in the repetitive portion, and of outputting the generated code, the generation and the outputting occurring when the repetitive portion is under the second repetition condition; and a switching code generation step of generating a switching code for switching between the first and second repetition codes, and of outputting the generated code as the compressed data.