Memory block quality identification in a memory device

摘要

If a memory block in a flash memory device is found to have a defect, a memory block quality indication is generated in response to the type of memory defect. This indication is stored in the memory device. In one embodiment, the quality indication is stored in a predetermined location of the defective memory block. Using the quality indication, it can be determined if a system's error correction code scheme is capable of correcting data errors resulting from the defect.

主权项

1. A method for implementing a memory block quality indication of a memory block in a system having an error correction code scheme, the method comprising:
reading the memory block quality indication from a first memory block having a defect, wherein the memory block quality indication is a predetermined code that indicates both: one of different types of memory defects and a quantity of memory cells of the first memory block that have that particular type of memory defect; determining a value of the memory block quality indication; determining a strength of the error correction code scheme; determining, in response to the determined strength of the error correction code scheme and the determined value of the memory block quality indication, if the first memory block is in a usable condition.