Research On The Technology Applied In Key Module Of EMMC Controller

In the era of Informationization, mobile device become more and more popular in all over the world, which get benefit from its characteristic of portable and the excellent human-computer interaction. As the big data era arrives, the need of memory capacity become larger and larger. In order to enhace the user experience, the memory system in mobile device gain much focus. One of such products targeting moblie device, namely e MMC, turn into main stream product in the storage system of mobile devices.Though eMMC become wide-spread, the key technology is still controlled by the famous storage manufacturer, such as Samsung electroinics, Micron, Toshiba,etc. In the domestic, neither IC design company nor Institution have probed into eMMC controller design. To bridge the gap, an eMMC controller design scheme is provided based on eMMC 4.5 specification in this paper.Firstly, a summary of NAND Flash technology and NAND Flash controller is provided and then the paper focus on eMMC controller and its specification. In connection with the characteristic of NAND Flash, the key management scheme and core optimization technology used in eMMC controller are discussed in the following chapter. Thirdly, through analysis of eMMC specification, a novel top-down design scheme of eMMC controller is presented. The proposed eMMC controller can be devided as two major parts named as module of data processing and module of command and core management respectively. Then, implemetation of a variety of NAND Flash management machanisms offered by eMMC specification are provided, such as trim operation, background operation, HPI management,etc. Meanwhile, core management algorithms like bad block management, address mapping and garbage collection which are normally applied in SSD are applied in the eMMC controller as a trial. Last but not least, a FPGA prototype of eMMC controller is designed. Fuctional verification of such prototype is performed via embedded ARM platform in order to ensure the compliance with eMMC specification. On the whole, based on the application scenario in mobile device, a design scheme of eMMC controller in consideration of both hardware complexity and system performance is proposed.