Power-fail protection circuit and method for storage device

Abstract

The invention relates to the field of electrocommunication and discloses a power-fail protection circuit and method for a storage device. The power-fail protection circuit comprises a control circuit and an energy storage element, wherein the control circuit is used for responding to a power-fail reset signal of a host system and disconnecting power supply connection between a host system and the storage device; under the situation that the power supply connection is disconnected, the energy storage element is used for supplying power to the storage device for a reset period of time. By means of the power-fail protection circuit and method for the storage device, the problem of reliability of flash equipment containing an FTL layer under the situation of accident power-fail can be solved, and thus the flash equipment containing the FTL layer can be applied to the network communication field which is high in reliability requirement.

Description

technical field [0001] The present invention relates to the field of electronic communication, in particular to a power-down protection circuit and method for storage devices. Background technique [0002] Storage devices composed of flash devices (hereinafter referred to as "flash devices") are widely present in portable electronic devices and computer devices. Flash devices usually consist of a controller plus a flash memory chip (eg, a NAND flash memory chip). Since the host interface is generally a file system interface, and the flash device is a block device, there is a controller between the flash device and the host interface serial bus USB to perform the mapping operation. The controller passes the flash translation layer (hereinafter referred to as "FTL") ) to perform the mapping operation. [0003] FTL is a translation layer between the NAND flash memory chip and the underlying file system, which enables the operating system and file system to access the flash dev...

AI Technical Summary

Problems solved by technology

[0005] However, there is a serious problem with the flash device containing FTL, that is, the FTL mapping table needs to be stored in the SRAM and DRAM inside the controller, and the mapping table is updated to the NAND flash memory chip after the data rewriting is completed.

If there is an unexpected power failure, the mapping table may be damaged. Once the mapping table is damaged, the flash device containing the FTL layer usually needs to be formatted, or it can no longer be read and written. It needs to be returned to the factory or use a special tool to restore it.

Therefore, although the existence of the FTL layer simplifies the difficulty of system design, it will lead to data unreliability, making flash devices such as USB disks unable to be used for data storage in areas with high data security requirements

[0006] However, for the above technical problems in the prior art, the NAND flash memory chip and the file system are mainly used instead of the FTL layer.

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