Storage device with power-off protection function, power-off protection method and computing system

Abstract

The invention provides a storage device and a power-off protection method therefor. The storage device comprises a host interface, a main control chip, an MRAM (Magnetic Random Access Memory) and one or more NAND chips, wherein the MRAM comprises a write cache or a read-write cache and a cache page table. The MRAM further comprises a write-back cache page table used for recording cache pages about to be written back to the NAND chips; if the operation of writing back the cache pages to the NAND chips is finished, a corresponding record of the write-back cache page table is deleted; and if the power is off in the process of writing back the cache pages to the NAND chips, the cache pages are rewritten back to the NAND chips when the power is on. According to the storage device and the power-off protection method provided by the invention, the cache pages about to be written back to the NAND chips are recorded in the MRAM, and if the power is off in the process of writing back the cache pages to the NAND chips, the cache pages are rewritten back to the NAND chips when the power is on, so that the data completeness can be ensured; and blocks about to be erased are further recorded in the MRAM, and if the power is off in the erasure process, the blocks are re-erased when the power is on, so that the data completeness is further ensured. The invention furthermore provides a computing system with a power-off protection function.

Description

technical field [0001] The invention relates to a storage device, in particular to a storage device with a power-off protection function, a power-off protection method and a computing system. Background technique [0002] Regarding Solid State Drives (SSD) and NAND: [0003] Currently, the development of NAND flash memory technology has promoted the SSD industry. Such as figure 1 As shown, high-speed serial interfaces such as SATA, PICe and other technologies are used between the SSD and the host. The interior consists of a set of NAND chips used to store data, DDR DRAM (memory) used to support calculations and cache data, and a main control chip (SSD Controller). Sometimes a power failure protection system is also required. [0004] Memory cards (SD or MicroSD cards, eMMC) used in devices such as mobile phones have a similar structure. It just replaces the DRAM chipset with a small amount of SRAM integrated in the control chip. [0005] NAND is a storage device that r...

AI Technical Summary

Problems solved by technology

However, the introduction of the write cache creates a new problem: once a power failure occurs, the content in the DRAM cache that has not been written to the NAND will be lost, causing the system to lose data or even damage the entire file system

[0013] However, in the absence of backup power, if a power outage occurs while writing data from MRAM back to NAND, then the data stored in NAND will be incomplete or bad

In fact, since most modern NAND chips have RAM cache inside, even if all the data has been input into the NAND chip, a sudden power failure may still destroy the data.

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