Method and device for compressing and expanding data pattern

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes:
• selectively distributing the respective divided unit data sequences in accordance with difference in their data structures into a plurality of blocks;
• counting a number of data changes of each said divided unit data sequence as a factor of difference in the data structure;
• and
• comparing said counted number of data changes with a threshold value;
• and
• selectively distributing the respective divided unit data sequences to a plurality of blocks in accordance with the comparison result;
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes:
• selectively distributing the respective divided unit data sequences in accordance with difference in their data structures into a plurality of blocks;
• determining whether the periodicity of data of each said divided unit data sequence is larger than a threshold value;
• and
• distributing the respective unit data sequences to a plurality of blocks in accordance with the determination result, and
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block, applying Burrows Wheeler transform (hereinafter referred to as BW transform) to a block in which the unit data sequences having a large periodicity of data larger than the threshold value are contained, and applying a run length compressing method to data transformed by BW transform;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes:
• selectively distributing the respective divided unit data sequences in accordance with difference in their statistical characteristic of data into a plurality of blocks;
• measuring an appearing probability of each symbol in each said unit data sequence and calculating an entropy of data from thus measured result;
• comparing the entropy of the data with a threshold value;
• and
• selectively distributing the respective divided unit data sequences to a plurality of blocks in accordance with the comparison results;
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and distributing the respective divided unit data sequences in accordance with difference in their data structure to a plurality of compressing blocks, wherein step (a) includes:
• counting a number of data changes of each said divided unit data sequence as a factor of difference in the data structure;
• measuring an appearing probability of each symbol in each said divided unit data sequence;
• calculating an entropy of the data based on measuring result of the appearing probabilities of the symbols;
• comparing the number of data changes with a threshold value of the number of data changes and also comparing the entropy of the data with an entropy threshold value;
• and
• selectively distributing the respective divided unit data sequences in accordance with the comparison results to a plurality of blocks which include a first block for containing the unit data sequence having its number of data change equal to or less than the threshold value, a second block for containing the unit data sequence having its number of data change larger than the threshold value and its entropy of the data equal to or less than the entropy threshold value, and a third block for containing the unit data sequence having its number of data change larger than the threshold value and its entropy of the data larger than the entropy threshold value;
• and
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes:
• compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

The data compressing method according to any one of claims 2, 5 and 13, wherein

• said dividing step (a) further includes the steps of:
• calculating threshold values for respective possibly appearable unit data sequences;
• estimating compression rates of the unit data sequences using the calculated threshold values;
• optimizing the threshold value so as to maximize the compression rate;
• and
• said compressing step (b) includes the steps of:
• using the optimized threshold value.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data, to an expanded data wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes:
• selectively distributing the respective divided unit data sequences in accordance with difference in their data structures into a plurality of blocks;
• applying BW transform to each the divided unit data sequence;
• counting a number of data changes of each the unit data sequence transformed by BW transform;
• calculating a compression rate from the number of data changes;
• obtaining the maximum value of compression rate and the number of application times of BW transform when the maximum value of compression rate is obtained;
• comparing the maximum value of compression rate with a threshold value of compression rate;
• and
• selectively distributing the divided unit data sequences into a plurality of blocks in accordance with the comparison results;
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

A data expanding method for expanding an inputted compressed data which has a uniform data type and is composed of a plurality of compressed unit data sequences, the respective compressed unit data sequences being compressed by different compressing methods according to difference at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted compressed data into the respective compressed unit data sequences, which are in turn distributed to a plurality of blocks in accordance with their compressing methods used for compression of the respective compressed unit data sequences, so that each block contains the compressed unit data sequences compressed by the same compressing method which is different from that of the other block, wherein the inputted compressed data is divided into compressed unit data sequences directly compressed by a run length compressing method and compressed unit data sequences compressed by the run length compressing method after application of BW transform;
• and
• (b) expanding the compressed unit data sequences contained in the respective blocks by using different expanding methods each corresponding to the compressing method of each blocks, wherein the compressed unit data sequences directly compressed by the run length compressing method are expanded by the run length expanding method to be outputted, and the compressed unit data sequences compressed by the run length compressing method after application of BW transform are expanded by the run length expanding method and thereafter the expanded data are transformed by inverse BW transform to be outputted.

A data expanding method for expanding an inputted compressed data which has a uniform data type and is composed of a plurality of compressed unit data sequences, the respective compressed unit data sequences being compressed by different compressing methods according to difference at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted compressed data into the respective compressed unit data sequences, which are in turn distributed to a plurality of blocks in accordance with their compressing methods used for compression of the respective compressed unit data sequences, so that each block contains the compressed unit data sequences compressed by the same compressing method which is different from that of the other block, wherein the inputted compressed data is a compressed data of a test pattern which is applicable to a semiconductor integrated circuit for its testing, and which is composed of a plurality of compressed test sequences, the respective test sequences being compressed by different compressing methods in accordance with difference at least either in their data structures or statistical characteristics of data and being applicable to respective pins of the semiconductor integrated circuit under test;
• and
• (b) expanding the compressed unit data sequences contained in the respective blocks by using different expanding methods each corresponding to the compressing method of each block, wherein the expanded unit data sequences are the expanded test sequences each correspondingly applicable to each said pin.

A test pattern compressing apparatus comprising

• a plurality of compressing means each having a different compressing method from one another;
• dividing means for dividing an inputted test pattern into test sequences each being for each of pins of an integrated circuit under test;
• and
• compressing method determining means for selecting suitable compressing means out of a plurality of compressing means in accordance with a data structure of each test sequence to compress the corresponding test sequence in the basis of each pin.

A test pattern compressing and expanding apparatus comprising:

• a plurality of compressing means each having a different compressing method from one another;
• dividing means for dividing an inputted test pattern into test sequences each being for each of pins of an integrated circuit under test;
• compressing method determining means for selecting suitable compressing means out of a plurality of compressing means in accordance with a data structure of each test sequence to compress the corresponding test sequence in the basis of a pin;
• compressed data dividing means for dividing an inputted data into compressed data each being for each pin of an integrated circuit under test;
• and
• a plurality of test sequence expanding means each for selecting an expanding method in accordance with a flag indicating a compressing method to apply the expanding method to the corresponding compressed data.

A test pattern compressing and expanding method including the steps of:

• dividing an inputted test pattern into test sequences each being for each of pins of an integrated circuit under test;
• selecting an appropriate compressing method in accordance with a data structure of each divided test sequence data to compress the test sequence in the basis of a pin;
• dividing an inputted compressed data into compressed data each being for each pin of an integrated circuit under test;
• and
• expanding each divided compressed data by an expanding method corresponding to the compressing method specified by a flag of the compressed data.

A test pattern compressing and expanding method including the steps of:

• dividing an inputted test pattern into test sequences each being for each of pins of an integrated circuit under test;
• selecting appropriate compressing methods in parallel in accordance with respective data structures of the divided test sequences to compress the respective test sequences in the basis of respective pins;
• dividing an inputted compressed data into compressed data each being for each pin of an integrated circuit under test;
• and
• expanding each divided compressed data by an expanding method corresponding to the compressing method specified by a flag of the compressed data.

A test pattern compressing apparatus comprising:

• a plurality of compressing means each having a different compressing method from one another;
• dividing means for dividing an inputted test pattern into test sequences each being for each of pins of an integrated circuit under test;
• and
• compressing method determining means for selecting suitable compressing means out of the plurality of compressing means in accordance with difference in statistical characteristics of data of each test sequence to compress the corresponding test sequence in the basis of each pin.

A data expanding method for expanding an inputted compressed data which has a uniform data type and is composed of a plurality of compressed unit data sequences, the respective compressed unit data sequences being compressed by different compressing methods according to difference at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted compressed data into the respective compressed unit data sequences, which are in turn distributed to a plurality of blocks in accordance with their compressing methods used for compression of the respective compressed unit data sequences, so that each block contains the compressed unit data sequences compressed by the same compressing method which is different from that of the other block, wherein the inputted compressed data is divided into compressed unit data sequences directly compressed by a run length compressing method, compressed unit data sequences compressed by the run length compressing method after application of BW transform, and compressed unit data sequences compressed by the other compressing methods;
• and
• (b) expanding the compressed unit data sequences contained in the respective blocks by using different expanding methods each corresponding to the compressing method of each block, wherein a run length expanding method is applied to the compressed unit data sequences directly compressed by the run length compressing method to output the expanded data, the run length expanding method is applied to the compressed unit data sequences compressed by the run length compressing method after application of BW transform and thereafter inverse BW transform is applied to the expanded data the number of times that BW transform was applied thereto at the compression time to output the expanded data, and an expanding method corresponding to one of the other compressing methods is applied to each of the compressed unit data sequences compressed by the other compressing methods to output the expanded data.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes selectively distributing the respective divided unit data sequences in accordance with difference in their data structures into plurality of blocks, wherein the inputted data is a test pattern which is applicable to a semiconductor integrated circuit for its testing, and the unit data sequences are test sequences of the test pattern, each said test sequence being applicable to each pin of the semiconductor integrated circuit under test;
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.

A data compressing and expanding method for compressing an inputted data to a compressed data and for expanding the compressed data to an expanded data, wherein the inputted data has a uniform data type and is composed of a plurality of unit data sequences and the respective unit data sequences are different at least either in their data structures or statistical characteristics of data, said method comprising the steps of:

• (a) dividing the inputted data to the respective unit data sequences and selectively distributing the respective divided unit data sequences in accordance with difference in their data structure into a plurality of compressing blocks, wherein step (a) includes selectively distributing the respective divided unit data sequences in accordance with difference in their statistical characteristic of data into a plurality of blocks, wherein the inputted data is a test pattern which is applicable to a semiconductor integrated circuit for its testing, and the unit data sequences are test sequences of the test pattern, each said test sequence being applicable to each pin of the semiconductor integrated circuit under test;
• (b) compressing the respective divided unit data sequences distributed to said plurality of compressing blocks using different compressing methods which are each suitable for each block to thereby obtain a compressed data, wherein step (b) includes compressing the respective unit data sequences distributed into said plurality of blocks using different compressing methods each of which is suitable for each block;
• (c) dividing the compressed data to respective compressed unit data sequences and distributing the thus divided respective compressed unit data sequences in accordance with their compressing methods used to a plurality of expanding blocks in accordance with difference in the compressing methods used;
• and
• (d) expanding the respective compressed unit data sequences contained in each of said plurality of the expanding blocks by using a suitable one expanding method which is selected for each said expanding block from different expanding methods so as to correspond to the compressing method used to the compressed unit data sequence.