Abstract: A method for screening bad columns applicable to a data storage medium is disclosed. The method for screening bad columns includes steps of: reading out written data of at least one of the data pages of at least one of the data blocks; comparing the written data with predetermined data to obtain a number of error bits in each of the columns in each of the segments in the at least one of the data pages, and accordingly calculating a total number of error bits in each of the segments; determining a segment having a largest total number of error bits from the segments, and determining and recording a column having a largest number of error bits from the segment having the largest total number of error bits as a bad column. A data storage device saving a bad column summary table is also disclosed.

Abstract: A method for screening bad columns applicable to a data storage medium is disclosed. The method for screening bad columns includes steps of: reading out written data of at least one of the data pages of at least one of the data blocks; comparing the written data with predetermined data to obtain a number of error bits in each of the columns in each of the segments in the at least one of the data pages, and accordingly calculating a total number of error bits in each of the segments; determining a segments having a largest total number of error bits from the segments, and determining and recording a columns having a largest number of error bits from the segment having the largest total number of error bits as a bad column. A data storage device saving a bad column summary table is also disclosed.

Abstract: A method for testing a storage apparatus, which includes: (a) writing a specific pattern to a storage unit of a storage apparatus; (b) reading the specific pattern written to the storage apparatus; (c) determining an error bit number of the specific pattern read in the step (b); and (d) determining that the storage unit has defect when the error bit number is larger than a error bit threshold value, wherein the error bit threshold value is smaller than a correctable bit number for a error correction code corresponding to the specific pattern.

Abstract: A method for testing a storage apparatus, which includes: (a) writing a specific pattern to a storage unit of a storage apparatus; (b) reading the specific pattern written to the storage apparatus; (c) determining an error bit number of the specific pattern read in the step (b); and (d) determining that the storage unit has defect when the error bit number is larger than a error bit threshold value, wherein the error bit threshold value is smaller than a correctable bit number for a error correction code corresponding to the specific pattern.