What is eMMC?
eMMC is an embedded non-volatile memory system, comprised of both flash memory and a flash memory controller integrated on the same silicon die. The eMMC solution consists of three components - the MMC (multimedia card) interface, the flash memory, and the flash memory controller - and is offered in the industry-standard BGA package.
Today’s embedded applications such as digital cameras, smart phones, and tablets almost always store their content on flash memory. In the past, this has required a dedicated controller to manage the reading and writing of data, driven by the application CPU. However, as semiconductor technology has evolved to allow vastly increased storage density, it has become inefficient for the controller to manage these functions from outside the flash memory die. Hence, eMMC was developed as a standardized method for bundling the controller into the flash die. As eMMC has improved, the standard has also provisioned for features such as secure erase and trim and high-priority interrupt to meet the demand for high performance and security. So while the eMMC standard was created to improve data rates and throughputs for high-density chips designed to store high-resolution video, newer generations are doing more for more applications, and each generation of the standard will include additional new features for a richer end-user experience.
The widely accepted standard for eMMC is v4.41 as defined in JESD84-A441: Embedded MultiMediaCard (e•MMC) Product Standard v4.41 published by JEDEC in April 2010. Recently, JEDEC has also published the JESD84-B45: Embedded MultiMediaCard (e•MMC), Electrical Standard (Version 4.5 Device) for eMMC v4.5 in June 2011.
Where is eMMC used?
eMMC is suitable for high performance applications such as portable consumer electronic products for e.g. smartphones, digital tablets, multi-media players, PDAs, navigational systems and digital cameras. eMMC can thus be used for mobile devices, enhanced storage solutions and as replacement for traditional storage media (i.e., HDDs).
What are the benefits of eMMC?
The eMMC architecture integrating the flash memory controller in the same package simplifies the application interface design and frees the host processor from low-level flash memory management. This benefits product developers by simplifying the non-volatile memory interface design and qualification process – resulting in a reduction in time-to-market as well as facilitating support for future flash device offerings.
In other words, eMMC hides the complexities of flash memory technology in a convenient "plug-and-play" package. The benefits this brings can be visualized as follows:
For a regular NAND flash-based product, the development stages would be roughly:
For a product using NAND memory, any changes in the chipset, operating system (OS), or the NAND memory requires changes to be made in the Flash Translation Layer (FTL), which in turn, requires testing the changes at the NAND level, significantly increasing delays for product level testing.
Compared to this, when eMMC is used, intermediate changes need not be tested, since the MMC interface takes care of everything. The development stages will be then:
Obviously, this reduces time and effort for developers.
Secondly, eMMC eliminates the need to develop interface software for all types of NAND memory by integrating the embedded controller into the memory chip and providing an easy-to-use memory solutions package for high-speed data transmissions by devices, such as mobile phones. It also eliminates the need for a memory expansion slot by stacking several memory functions vertically, resulting in a very small footprint for the memory devices.
Further, this design makes it possible to select suppliers for subcomponents from a wider base, which results in increased revenues with lower time-to-market.
What is the required software support for eMMC?
The eMMC v4.41 standard provides performance, security and reliability features such as high-priority interrupt and secure erase. These features, such as secure erase and secure trim, require software support from the file system beyond the driver, without which, the application call will not reach the storage media via the file system. Any organization, planning to move to eMMC, would need to provision for such software support from internal or external sources.
With the eMMC applications market forecasted to expand to over 700 million units in 2013, there is a need for flash drivers and file systems such as those made by Datalight to specifically support eMMC standards so as to fully utilize the security features offered by them.
What is the future for eMMC?
Shipments of eMMC solutions in 2013 are forecast to reach 711.1 million units, up from 520.3 million in 2012, according to an IHS iSuppli Mobile & Embedded Memory market brief from information and analysis provider IHS. [1]
Approximately 23 percent of all handsets in 2011—equivalent to some 239.7 million units—featured eMMC, with the percentage to rise to 37 percent in two years’ time. Other important eMMC segments include tablets, e-book readers and portable navigation devices with global positioning systems (GPS). Also in place of the lower-density memory that camcorders and set-top boxes now use, those devices also are looking at the feasibility of using eMMC, which provides a cost-effective, long-term solution with standardized pinouts. [2]
Though eMMC will continue to dominate the market for cellphone NAND memory for the next few years, the increasing demand for data security in wireless platforms will favor the rising usage of UFS (Universal Flash storage) in the future. Still, as UFS parts won’t be as cost competitive as eMMC given their high manufacturing expense, smartphone manufacturers will not share the same urgency to switch their storage needs to UFS, even for bleeding-edge smartphone platforms.
Moreover, the most current eMMC 4.5 revision with up to 200 megabyte-per-second performance is not only sufficient for even high-end devices, it also provides a far smoother transition than UFS for mainstream device platforms in terms of system compatibility.
Lastly, an earlier-specification product known as eMMC 4.41 continues to claim a sizable contingent of devices that prefer to stick to the older eMMC version instead of incurring the additional expense of switching to eMMC 4.5. With the 4.41 revision satisfying the performance and security needs of most device segments, it is considered the most effective way to utilize high- density NAND for many consumer electronics applications, including entry-level smartphones, ereaders, TVs, set-top boxes and portable music players. With Google’s Android OS requiring 4 GB of storage, there is even more impetus for manufacturers of portable handsets to turn to eMMC to obtain low-cost flash memory and trim their costs as much as possible.
Conclusion
The benefits of using eMMC by consumer electronics manufacturers and related software developers points will undoubtedly lead to a growth in usage of eMMC in the next few years, especially in areas of digital cameras, smartphones, mobile devices and navigation devices. These applications will require mature file system and driver products such as those made by Datalight to fully leverage the benefits of the technology.
Read more: http://www.datalight.com/solutions/technologies/emmc/what-is-emmc#ixzz2NDtzkVnx
