Solid-state drive using MRAM and read-write cache management method

Abstract

The invention provides a solid-state drive using an MRAM (Magnetic Random Access Memory). The solid-state drive comprises a main control chip, a group of NAND chips and the MRAM, wherein the NAND chips are used for storing data; the NAND chips and the MRAM are connected with the main control chip; the MRAM comprises a read-write cache and a cache table; and the cache table comprises read-write weights of a cache page in the read-write cache. The solid-state drive and a read-write cache management method provided by the invention have the advantages that the MRAM comprises the read-write cache; the speed for reading and writing the MRAM is much higher than the speed for reading and writing the NAND, so that the read-write performance of the solid-stage drive can be improved; meanwhile, the number of times for writing the NAND is reduced; the service life of the NAND is prolonged; through the read-write weights, a frequently operated page is remained in the read-write cache, so that the read-write performance of the solid-state drive is improved; different weight values are given to the read-write operations; the number of times of writing back the NAND can be effectively reduced, so that the service life of the NAND is prolonged; a power failure protection system does not need to be used; the cost of the solid-state drive is reduced; and meanwhile, the power consumption is reduced.

Description

technical field [0001] The invention relates to a solid-state hard disk, in particular to a solid-state hard disk using MRAM and a read-write cache management method. Background technique [0002] Currently, the development of NAND flash memory technology has promoted the SSD industry. like 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. [0003] NAND is a storage device that reads and writes in blocks. The smallest readable unit is called a page, and the smallest erasable unit is called a block. A block is often composed of many pages. After the block is erased, the Pages can be written individually. Write operations are slow, much slower than read operations, a...

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

And MRAM is not compatible with standard CMOS semiconductor process like DRAM and Flash

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