MultiMediaCard#DV-MMC
{{short description|Memory card format}}
{{distinguish|SD card}}
{{Infobox media
| logo =
| image = 15-04-29-MMC-Karte-RalfR-dscf4734-d.jpg
| caption = 32 MB MMCplus card
| type = Memory card
| capacity = Up to 512 GB
| read =
| write =
| standard =
| owner = JEDEC
| use = Portable devices
| dimensions = {{cvt|32|xx|24|xx|1.4|mm|1}}
| weight = {{cvt|2|g}}
| extended from =
| extended to = Secure Digital (SD)
| released = 1997
}}
{{Memory types}}
MultiMediaCard (MMC) is a memory card standard used for solid-state storage, originally introduced in 1997 by SanDisk, Siemens, and Nokia. Designed as a compact, low-pin-count, postage‑stamp‑sized card alternative to earlier storage solutions, MMC uses a serial interface and a single memory stack assembly, making it smaller and simpler than high-pin-count, parallel-interface cards such as CompactFlash, which was previously developed by SanDisk.
It has since evolved into several variants, including the widely used SD card and the eMMC (embedded MMC) which is soldered directly onto a device's circuit board. While removable MMC cards have largely been supplanted by SD cards, eMMC remains common in low-cost smartphones, tablets, and budget laptops due to its compact size and affordability, despite being slower and less upgradeable than modern solid-state drives
History
File:MMC card vs SDHC card undersides angle.jpgIn 1994, SanDisk introduced the CompactFlash format, one of the first commercially successful flash memory card types. CompactFlash outpaced competing formats of the time, including the Miniature Card and SmartMedia. However, the late 1990s saw a proliferation of proprietary memory card formats, such as Memory Stick from Sony and the xD-Picture Card developed by Olympus and Fujifilm, leading to a fragmented and incompatible landscape for removable storage.{{Cite web |last=Shendar |first=Ronni |date=September 29, 2022 |title=The Invention of the SD Card: When Tiny Storage Met Tech Giants |url=https://blog.westerndigital.com/invention-sd-card/ |access-date=June 19, 2025 |website=Western Digital}}
In response to this fragmentation, SanDisk partnered with Siemens and Nokia in 1996 to create a universal, compact memory card standard. The resulting format, known as the MultiMediaCard (MMC), was officially introduced in 1997. MMC was designed to be significantly smaller than CompactFlash, with a postage stamp-sized form factor, and to use just seven flat electrical contacts and a simplified serial interface, reducing complexity in host devices. The MultiMediaCard Association (MMCA), was founded in 1998 by 14 companies to promote adoption of the format.{{Cite web |title=MMCA: Association Backgrounder |url=http://mmca.org/press/backgrounder.html |archive-url=https://web.archive.org/web/20050208222932/http://mmca.org/press/backgrounder.html |archive-date=February 8, 2005 |access-date=June 23, 2025 |website=mmca.org}}
Compared to the physically larger CompactFlash, which relied on 50-pin parallel interfaces and traditional surface-mount assembly, MMC offered a more streamlined and mobile-friendly design, which the MMCA hoped would make it attractive for use in portable consumer electronics such as digital cameras, handheld devices, and mobile phones.
Despite its technical advantages, MMC adoption was limited. Even Nokia, one of the original backers, was slow to integrate MMC into its popular handsets. In an effort to boost adoption, the MMCA introduced revised specifications between 2004 and 2007, including reduced power consumption, support for smaller form factors, and increased storage capacities. However, these updates had limited market impact.
MMC technology served as the foundation for the development of the Secure Digital (SD) card standard. Introduced in 1999 by SanDisk, Panasonic, and Toshiba, SD was based on the MMC electrical interface but added digital rights management (DRM), more durable casing, and a mechanical write-protect switch. These enhancements, along with broad manufacturer support, led SD to surpass MMC in popularity. Many early SD-compatible devices also supported MMC cards.{{Cite web |date=August 25, 1999 |title=Three Giants to develop new "Secure Memory Card" |url=https://www.dpreview.com/articles/6861681955/newmemory |access-date=June 19, 2025 |website=Digital Photography Review}}
MMC's most enduring legacy came in the form of its embedded variant, eMMC (embedded MultiMediaCard). First introduced by the JEDEC Solid State Technology Association in 2006 with version 4.0 of the standard, eMMC adapted the MMC architecture for non-removable storage integrated directly onto a device’s motherboard. The eMMC format proved especially successful in smartphones, tablets, Chromebooks, and other low-cost computing devices due to its low cost, compact size, and adequate performance for basic tasks.
On September 23, 2008, the MMCA formally transferred control of the MMC specification to JEDEC.{{Cite press release |title=MultiMediaCard Association Merges with JEDEC |date=September 23, 2008 |url=https://www.jedec.org/news/pressreleases/multimediacard-association-merges-jedec |access-date=October 29, 2022 |website=JEDEC}} While JEDEC continued to update the eMMC standard, removable MMC cards saw little further development. {{As of|2025}}, the format has largely faded from use. eMMC itself is gradually being supplanted in performance-oriented applications by newer technologies such as Universal Flash Storage (UFS) and solid-state drives (SSDs), although it remains in use in budget-conscious and embedded devices.
MMC card variants
{{multiple image
| align = right
| direction = vertical
| width =
| header =
| image1 = Four MMC cards front.jpg
| alt1 = Front of four different MMC cards: MMC, RS{{nbhyph}}MMC, MMCplus, MMCmobile, and metal extender
| caption1 = Top of four types of MMC cards (clockwise from left): MMC, RS-MMC, MMCplus, MMCmobile, metal extender
| image2 = 01fourcardsrev.curve.jpg
| alt2 = Back of four different MMC cards (same cards as above)
| caption2 = Bottom of the same four cards
}}
= RS-MMC =
Reduced Size MultiMediaCard (RS{{nbhyph}}MMC), introduced in 2002,{{Cite web |date=November 11, 2002 |title=Reduced Size MultiMediaCard Standard Approved by MMCA |url=http://mmca.org/press/RS-MMC-final.PDF |archive-url=https://web.archive.org/web/20050208220807/http://mmca.org/press/RS-MMC-final.PDF |archive-date=February 8, 2005 |access-date=June 23, 2025 |website=mmca.org}} is a smaller variant of MMC, measuring approximately {{Convert|24|x|18|x|1.4|mm}}, about half the height of a standard MMC.{{Cite web |last=Kolokowsky |first=Steve |date=July 3, 2006 |title=Untangle the web of removable storage |url=https://www.eetimes.com/untangle-the-web-of-removable-storage/ |access-date=June 23, 2025 |website=EE Times}} It uses a simple extender to work in standard MMC or SD slots and was available in capacities up to 2 GB. Some manufacturers, including Nokia and Siemens, briefly adopted RS{{nbhyph}}MMC in their early Symbian-based smartphones and tablets.
= DV-MMC =
Dual Voltage MMC (DV{{nbhyph}}MMC, also called the Low Voltage MMC) supported 1.8 V alongside the normal 3.3 V operation to reduce power consumption in mobile devices. This variant was first proposed in 2001,{{Cite press release |title=MultiMediaCard Association Approves System Specification 3.1 |date=June 27, 2001 |url=http://www.mmca.org/press/press010627b.pdf |access-date=June 23, 2025 |archive-url=https://web.archive.org/web/20041020003713/http://www.mmca.org/press/press010627b.pdf |archive-date=October 20, 2004 |website=MultiMediaCard Association}} but wasn't widely available until 2004,{{Cite press release |title=Samsung Launches Dual Voltage Memory Card for Mobile Appliances |date=March 29, 2004 |url=http://www.mmca.org/news/Samsung-Dual-Voltage-MMC1.pdf |access-date=June 23, 2025 |archive-url=https://web.archive.org/web/20050305171455/http://www.mmca.org/news/Samsung-Dual-Voltage-MMC1.pdf |archive-date=March 5, 2005 |website=Samsung}} and was soon overtaken by the more capable MMCplus and MMCmobile formats.
= MMCplus, MMCmobile and MMCmicro =
The MMCplus and MMCmobile formats were introduced in 2004 and the MMCmicro format in 2005 as part of version 4 of the MMC specification with several enhancements to improve performance and better compete with SD cards.{{Cite press release |title=MultiMediaCard Specification Version 4.0 is Released |date=February 2, 2004 |url=http://www.mmca.org/press/MMCA-SpecV-4.pdf |access-date=June 23, 2025 |url-status=dead |archive-url=https://web.archive.org/web/20050305192601/http://www.mmca.org/press/MMCA-SpecV-4.pdf |archive-date=March 5, 2005 |website=MultiMediaCard Association}}{{Cite press release |title=MultiMediaCard Association Announces MMCplus and MMCmobile Cards |date=September 20, 2004 |url=http://www.mmca.org/press/NewBranding.pdf |access-date=June 23, 2025 |archive-url=https://web.archive.org/web/20050305171127/http://www.mmca.org/press/NewBranding.pdf |archive-date=March 5, 2005 |website=MultiMediaCard Association}}{{Cite press release |title=The MultiMediaCard Association Finalizes MMCmicro Card Specification |date=July 21, 2005 |url=http://www.mmca.org/press/MMCmicroFinal.pdf |access-date=June 23, 2025 |archive-url=https://web.archive.org/web/20061010173014/http://www.mmca.org/press/MMCmicroFinal.pdf |archive-date=October 10, 2006 |website=MultiMediaCard Association}} These enhancements included support for higher clock speeds (26 MHz and 52 MHz alongside the normal 20 MHz) and wider data buses (8{{nbhyph}}bit alongside the previous 1- and 4{{nbhyph}}bit), which combined to enable a 52 Mbit/s transfer rate, alongside dual-voltage support (1.8 V and 3.3 V) carried over from DV‑MMC.
The full‑size enhanced format was marketed as MMCplus, while its smaller counterpart, matching the size of RS-MMC, was known as MMCmobile. Cards have 13 flat electrical contacts to support 8{{nbhyph}}bit data buses. Both formats maintained backward compatibility with devices with standard MMC readers, though without support for some of their advanced features.{{Cite web |date=2005 |title=MultiMediaCard Brochure |url=http://www.mmca.org/press/mmca_brochure_120204-final-lores.pdf |archive-url=https://web.archive.org/web/20050408190720/http://www.mmca.org/press/mmca_brochure_120204-final-lores.pdf |archive-date=April 8, 2005 |access-date=June 23, 2025 |website=MultiMediaCard Association}}
The MMCmicro format featured a compact {{Convert|14|x|12|x|1.1|mm}} form factor to compete with microSD cards. It supported dual-voltage and high-speed 4‑bit operation, though it lacked the pins required for an 8‑bit bus. MMCmicro cards could be used with an adapter for use in full-size MMC slots.
= MiCard =
The miCARD (Multiple Interface Card) was a high‑capacity MMC variant proposed in 2007 that could be plugged directly into a USB port eliminating the need for dedicated card slots or separate card readers and could be used in standard MMC/SD slots via an adapter.{{Cite press release |title=MultiMediaCard Association Announces Specification for Multiple-Interface Memory Cards |date=May 31, 2007 |url=http://www.mmca.org/home/MMCA_MiCard_052907_FINAL.pdf |access-date=June 23, 2025 |archive-url=https://web.archive.org/web/20070706114800/http://www.mmca.org/home/MMCA_MiCard_052907_FINAL.pdf |archive-date=July 6, 2007 |website=MultiMediaCard Association}} The card would have been slightly smaller than a RS-MMC/MMCmobile card, but larger than MMCmicro at {{Convert|21|x|12|x|1.95|mm}}.{{Cite web |last=Melanson |first=Donald |date=May 31, 2007 |title=MMCA announces MiCard specification for MMC / USB combo cards |url=https://www.engadget.com/2007-05-31-mmca-announces-micard-specification-for-mmc-usb-combo-cards.html |access-date=June 23, 2025 |website=Engadget |language=en-US}} Despite backing from several Taiwanese companies, MiCard never reached mass production.
Embedded MMC {{anchor|eMMC}}
File:Samsung Galaxy Tab 2 10.1 - Samsung KLMAG2GE4A-A002-3955.jpg]]
The embedded MultiMediaCard (eMMC, officially branded as e•MMC) is a type of internal storage that integrates NAND flash memory,{{Cite web |date=September 6, 2016 |title=NAND and eMMC: All You Need to Know About Flash Memory |url=https://www.makeuseof.com/tag/nand-emmc-need-know-flash-memory/}} a buffer, and a controller into a single ball grid array (BGA) package. Unlike other forms of removable card-based MMC storage, eMMC is permanently soldered onto a device's printed circuit board (PCB) and is not user-removable or upgradeable. The onboard controller manages tasks such as error correction and data handling, reducing the workload on the device's main processor. eMMC chips use an 8-bit parallel interface and are available in various physical sizes and storage capacities.{{Cite web |title=Flash Memory Form Factors |url=https://www.hyperstone.com/en/Registration-Hyperstone-1125.html |url-access=registration |access-date=April 19, 2018 |series=The Fundamentals of Reliable Flash Storage |publisher=Hyperstone GmbH}}{{Cite web |title=What is eMMC Memory – software support – Reliance Nitro |url=http://www.datalight.com/solutions/technologies/emmc/what-is-emmc |website=datalight.com}}
The eMMC standard was first introduced by the JEDEC Solid State Technology Association in 2006 with version 4.0, which adapted the original card-based MMC specification for embedded (non-removable) and mobile applications.{{Cite web |title=What is eMMC? (embedded MultiMediaCard) |url=https://www.techtarget.com/searchstorage/definition/eMMC-embedded-MultiMediaCard |access-date=June 22, 2025 |website=TechTarget |publisher=SearchStorage}} Between 2007 and 2012, the version 4 standard was revised multiple times to improve performance and introduce features such as secure erase and on-system firmware updates. Version 5.0, released in 2013, introduced the HS400 interface mode, enabling theoretical data transfer speeds of up to 400 MB/s, along with enhancements to reliability and boot performance. This was followed by version 5.1 in 2015, which added command queuing and further reliability improvements.{{Cite web |last=Hunt |first=Cale |date=October 2, 2024 |title=eMMC vs. SSD storage: What was the difference, and does it matter now? |url=https://www.windowscentral.com/hardware/emmc-vs-ssd-storage-what-was-the-difference-and-does-it-matter-now |website=Windows Central}} The most recent update, version 5.1A, was released in 2019 and included minor refinements to the standard.{{Cite web |date=February 27, 2019 |title=JEDEC Publishes New UFS, e.MMC, and SPI NOR Flash Standards |url=https://www.jedec.org/news/pressreleases/jedec-publishes-new-ufs-emmc-and-spi-nor-flash-standards |access-date=June 22, 2025 |website=JEDEC}}
eMMC became widely used as the primary storage medium in early smartphones, and later in low-cost laptop computers, Chromebooks, tablet computers, and other compact computing devices. While it was gradually supplanted in higher-performance devices by alternatives such as Universal Flash Storage (UFS) in smartphones and solid-state drives (SSDs) in computers, eMMC continued to be used in entry-level products due to its low cost,{{Cite web |title=eMMC Chips |url=https://www.mouser.com/c/semiconductors/memory-ics/emmc/?sort=pricing}} compact form factor, low power consumption, and adequate performance for everyday tasks such as web browsing, email, and video streaming.
While eMMC is faster and more power-efficient than traditional hard disk drives, it is slower than most SSDs, especially those using NVMe over PCI Express. These speed limitations make it less suited for applications involving large files or intensive computing needs, such as gaming or video editing. Its lack of upgradeability also limits its appeal in more advanced systems, as users cannot replace or expand storage after purchase.
class="wikitable"
! Version !Introduced ! Sequential read (MB/s) ! Sequential write (MB/s) ! Random read (IOPS) ! Random write (IOPS) |
4.5
|2012 | 140 | 50 | 7,000 | 2,000 |
---|
5.0
|2013 | 250 | 90 | 7,000 | 13,000 |
5.1
|2015 | 250 | 125 | 11,000 | 13,000 |
Similar formats
In 2004, a group of companies—including Seagate and Hitachi—introduced an interface called CE-ATA for small form factor hard disk drives.{{Cite web |title=New Consumer Electronic Interface on Future Hard Drives |url=https://phys.org/news/2004-09-consumer-electronic-interface-future-hard.html |access-date=April 1, 2019 |website=Phys.org}} This interface was electrically and physically compatible with the MMC specification. However, support for further development of the standard ended in 2008.{{Cite web |title=Consumer Electronics ATA (CE-ATA) |url=https://www.techopedia.com/definition/26017/consumer-electronics-ata-ce-ata |access-date=April 1, 2019 |website=Technopedia}}
The game card format used on the PlayStation Vita was found to be based on the MMC standard, but with a different pinout and support for custom initialization commands as well as copy protection.{{Cite web |date=August 25, 2016 |title=Playstation Vita Cartridge Dump explained |url=https://wololo.net/2016/08/25/playstation-vita-cartridge-dump-explained/ |access-date=July 29, 2022 |website=Wololo.net |language=en-US}}
See also
References
{{Reflist}}
External links
{{Commons category|Multi Media Card}}
- [https://www.jedec.org/standards-documents/technology-focus-areas/flash-memory-ssds-ufs-emmc/e-mmc eMMC Standard] – JEDEC.org
{{Memory Cards}}
{{Use mdy dates|date=June 2025}}