Wednesday, June 13, 2012

e-MMC (Embedded MultiMedia Card)

     eMMC describes an architecture consisting of an embedded storage solution with MMC interface, flash memory and controller.In one line it is a flash/nand over MMC interface. Typically, flash memory is controlled by a dedicated controller that supervises data reads and writes, and operates under the control of the application's CPU.

     eMMC is a standard for embedded memory devices that contain not only a data storage element (such as NAND flash memory), but also a controller for the storage element integrated on the same silicon die. This results in several advantages, such as reduced development time and easier integration of the memory block in the overall system. Ultimately, this leads to a much shorter time-to-market for the end product.



  e·MMC embedded memory essentially transforms a program/erase/read device like NAND Flash into a simple write/read memory. This managed interface addresses potential NAND design concerns internally, using error correction code (ECC), wear leveling, and bad block management technology. Handling errors internally takes the burden off the host controller and increases speed, providing higher system performance.Managed NANDs are RAW NANDs combined with a memory controller and can support popular interfaces such as MMC (eMMC, moviNAND), SD (eSD) and SPI. The memory controller hides the details of the NAND and provides the intended interface and ECC support. This means that a eMMC/eSD NAND can talk to a embedded TI device through MMC/SD controller.

Composition of an e-MMC System
An e-MMC system generally consists of a host controller, an e-MMC device, and a HS-MMC driver, which is software that controls the e-MMC (see below).

  1. The host controller has a host CPU and a HS-MMC interface. The e-MMC also has a HS-MMC interface.
  2. The e-MMC consists of raw MLC NAND flash memory and a controller. The controller has a HS-MMC interface which can be connected to the host controller. It also has a NAND interface which is connected to the raw MLC NAND flash memory. It has several functions such as bad block management, wear leveling and error correction code (ECC), to utilize the raw MLC NAND flash memory efficiently.
  3. The HS-MMC driver handles operations between the host controller and the e-MMC.

1 comment:

danish said...

I Like to add one more important thing here, North America is expecting the highest growth for embedded multimedia card market worldwide as tremendous growth of 3G penetration across the region.