Flash memory controller and method thereof

Abstract

A flash memory controller comprises a flash memory interface controller, a host interface controller, a random-access memory (RAM) interface controller, an ECC encoder, an ECC divider, an ECC constructor and an ECC decoder. The flash memory interface controller is configured to store information data, ECC segments, and linked-lists to a flash memory and read information data, ECC segments, and the linked-lists from the flash memory. The host interface controller is configured to forward information data to a host and to receive information data from the host. The RAM interface controller is configured to store the linked-lists to a RAM device and read the linked-lists from the RAM device. The ECC encoder is configured to receive a write information datum from the host interface controller and generate an ECC datum, of which the length is variable, in response to the write information datum to be stored in the flash memory when operated in a write mode. The ECC divider is configured to divide the generated ECC datum into a plurality of ECC segments according to the length of the generated ECC datum and forward the divided ECC segments to the flash memory interface controller when operated in a write mode. The ECC constructor is configured to receive a plurality of ECC segments from the flash memory interface controller and construct an ECC datum by combining the received ECC segments for a read information datum received from the flash memory when operated in a read mode. The ECC decoder is configured to correct errors of the read information datum based on the read information datum and the constructed ECC datum and forward the corrected read information datum to the host interface controller when operated in a read mode. In addition, the link relation of the ECC segments in the flash memory is indicated by the linked-lists.

Description

technical field [0001] The present invention relates to flash memory, and more particularly to methods and systems for error correction codes for flash memory. Background technique [0002] Due to continuous advances in functionality, flash memory has become an alternative to traditional motor-driven disks in various applications such as portable devices. Since flash memory has no mechanical components, compared with motor-driven disks, flash memory has the advantages of anti-vibration, low power consumption, and high speed. However, there are still some limitations in the flash memory, one of which is that each read / write unit in the flash memory needs to perform an erase operation (EraseOperation) before writing to erase the previous data. Another limitation is that each read / write unit in the flash memory has a limit on the number of erasing / writing times, exceeding the limit will cause bit damage and damage user data. [0003] Traditionally, technologies such as error ...

AI Technical Summary

Problems solved by technology

Once marked as a damaged flash block, all flash pages located in the damaged flash block will no longer be accessible

If other flash pages in the damaged flash block still have the ability to correct errors, such a mark will cause a waste of resources

Images