| 摘要 |
Cross-decoding assists decoding of an otherwise uncorrectable error when decoding a desired page of a multi-level-cell technology flash memory. A solid-state disk (SSD) controller adjusts space allocated to redundancy respectively within various pages (e.g. upper, middle, and lower pages) such that the respective pages have respective effective Bit Error Rates (BER)s, optionally including cross-decoding, that approach one another. Alternatively the controller adjusts the allocation to equalize decoding time (or alternatively access time), optionally including decoding time (accessing time) accrued as a result of cross-decoding when there is an otherwise uncorrectable error. The adjusting is via (a) respective ratios between allocation for ECC redundancy and user data space, and/or (b) respective coding rates and/or coding techniques for each of the various pages. Alternatively the controller adjusts the allocation to maximize total usable capacity by allocating to redundancy and data for the various pages, assuming that cross-decoding is to be used. |
