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e.MMC FAQs

Managed NAND
eMMC(17)
What is e.MMC?

Embedded MultiMediaCard (e.MMC) is a NAND Flash-based memory solution defined by JEDEC that comes in a small BGA package. JEDEC defines both the hardware and software, enabling easy customer design-in and the ability to multisource.

What are the benefits of e.MMC?

e.MMC is a fully managed solution (all media management and ECC are handled internally), making NAND technology transitions invisible to the host and providing customers with the ability to reduce their time-to-market and to sustain products longer and more easily.

What does the term "broad market" signify?

Our embedded market e.MMC products are divided into two families: automotive and broad market. This is due to the unique requirements that are required in the automotive market; thus, there is a separate product line supported by Micron’s automotive team. Broad market covers all other market segments such as consumer, gaming, server, networking, industrial, medical, military, etc. Broad market e.MMC includes two sub-families: WT with commercial temperature grade and IT with an extended temperature range.

How can I order samples?

You can order samples through the Micron Sample Center.

Is it necessary to refer to the JEDEC specification as well as to Micron’s data sheet?

Yes, the JEDEC specification has to be read in conjunction with the data sheet. Micron e.MMC complies with the JEDEC standard; hence, Micron's data sheets provide information that is specific only to Micron’s e.MMC devices.

The JEDEC specification (Standard No. 84-A441) is available at: www.jedec.org/sites/default/files/docs/JESD84-A441.pdf

Are simulation models available?

Yes, IBIS models are available for WT and IT products (JEDEC 153-/169-ball and 100-ball); functional models (such as Verilog) are under evaluation.

What is the e.MMC offering for industrial applications?
Micron is offering an extensive number of solutions for industrial customers, such as five densities and JEDEC-standard BGA 153-/169-ball and custom 100-ball packaging. All of these products will operate in the extended temperature range of -40° to 85°C.
What are the advantages of 100-ball IT e.MMC?

Micron’s 100-ball e.MMC BGA package features a 1.0mm ball pitch for board routing simplification (saving PCB costs) and improved board-level reliability (temp cycling). This solution is particularly attractive to automotive, industrial, and networking market segments. See the following table for additional benefits.

Features of 100-ball e.MMC

Benefits

Large 1.0mm ball pitch

  • Allows for low-cost PCB trace/space designs
  • Simplifies PCB routing
  • Enables a reduction in the number of PCB layers
  • Reduces costs via a lower drill size
  • Lower DAR (drill aspect ratio) for better PCB yields
  • Allows for wider traces for better thermal dissipation

Large 0.45mm nominal ball diameter

  • Provides high PCB board-level reliability
  • Improves surface-mount yields (vs. smaller ball packages)
  • Provides better thermal dissipation

Low ball count (compared to 153-ball e.MMC JEDEC-standard)

  • Allows for easier, low-cost PCB routing
  • Reduces package and PCB costs

100-ball pattern contains 12 mechanical support balls (3 in each corner)

  • Provides excellent PCB board-level reliability
  • Allows for flexible “large package size” variations

Flexible ball-out design

  • Allows for future e.MMC feature upgrades and next-generation technology
Is Micron the only provider of 100-ball IT e.MMC?

Greenliant Systems offers pin-compatible 100-ball IT e.MMC for those customers requiring a second source. The NANDrive GLS85VM e.MMC product family supports the JEDEC 4.4 standard and operates at full industrial temperature of -40°C to +85°C. The product line is targeted for industrial and the broad market. For further information and support contact: www.Greenliant.com.

Does Micron's e.MMC support SPI mode?

Micron’s e.MMC 4.41 products are compliant to the JEDEC standard. JEDEC removed this feature when introducing the e.MMC 4.3 specification; therefore, SPI mode is not supported. 

Is v. 4.41 e.MMC functionality backward-compatible to v. 4.3?
Yes, v. 4.41 functionality is backward-compatible with v. 4.3; a v. 4.41 e.MMC device will work with a v. 4.3 or v. 4.4 MMC host. The v. 4.41 devices support additional features such as boot and RPMB partitions, high-priority interrupt, background operation, write reliability, and enhanced reliable write.
How can I migrate from Micron e.MMC 4.4 to 4.41?

Micron has EOL’d its e.MMC 4.4 offering. Refer to your AE for support. A dedicated technical note “TN-FC-08: Migrating from Micron v. 4.4 e.MMC to 4.41 e.MMC” is available for review.

Is it possible to perform a system boot from e.MMC?

Yes, e.MMC provides two boot partitions to provide fast access to boot code for improved system boot time. Booting from boot partitions can provide access to stored data in ~50ms, whereas booting from the user area can take hundreds of milliseconds. However, in order to utilize the boot partitions, the chipset must be able to support booting from the boot partition. Check with your chipset vendor to understand if booting from the e.MMC boot partitions is supported.

For more information, refer to “TN-FC-06: Booting from Embedded MMC - JEDEC 4.41.

Does Micron e.MMC support power-loss protection?

Yes, ESG e.MMC devices support static data protection. Devices are shipped from Micron factories as COMBO with a configuration optimized for best write performance. Customers can reconfigure the devices to protect static (previously written) data if there is power loss during a write operation.

What are the enhanced technology features mentioned in JEDEC specification, and what are the benefits?

A part or all of the MLC user space can be configured as pseudo-SLC. The partition offers better reliability, endurance, and performance compared to MLC NAND.

Can I set up partitions within e.MMC to suit different usage models?

The e.MMC specification allows customers to configure the user data area into a maximum of four separate partitions that can each be configured as MLC (default) or enhanced mode (pSLC). Enhanced mode provides better reliability in exchange for twice the space as MLC.

For more information refer to “TN-52-07: e.MMC Partitioning.

What is the required software support for e.MMC?

e.MMC drivers are generally available on the market due to the fact that it is an industry-standard product.

The e.MMC v. 4.41 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.

Linux supports e.MMC and allows the integration within its subsystems and the Android file system. The advanced features introduced by the JEDEC specification have been supported by patches initially and have only very recently been included in the kernel. See Micron technical note TN-52-05 for details about e.MMC Linux enablement for new features by JEDEC 4.4–4.41.

Proprietary software solutions are available on the market as well.