Editing MultiMediaCard

{{short description|Memory card format}}
{{distinguish|SD card}}
{{Infobox media
| logo          = 
| image         = 15-04-29-MMC-Karte-RalfR-dscf4734-d.jpg
| caption       = 32&nbsp;[[Megabyte|MB]] MMCplus card
| type          = [[Memory card]]
| capacity      = Up to 512&nbsp;GB
| read          = 
| write         = 
| standard      = 
| owner         = [[JEDEC]]
| use           = Portable devices
| dimensions    = Standard: 32&nbsp;×&nbsp;24&nbsp;×&nbsp;1.4&nbsp;mm
| weight        = Standard: ~2.0 g
| extended from =
| extended to   = [[Secure Digital]] (SD)
| released      = 1997
}}
{{Memory types}}

'''MultiMediaCard''', officially abbreviated as '''MMC''', is a [[memory card]] standard used for [[solid-state storage]]. Unveiled in 1997 by [[SanDisk]] and [[Siemens]],<ref>{{cite book |url=https://www.tomshardware.com/reviews/flash-removable-storage-ssd-drive,3626-3.html |title=Upgrading And Repairing PCs 21st Edition |publisher=Que Publishing |author=Scott Mueller |date=3 August 2014 |isbn=978-0789750006 }}</ref> MMC is based on a surface-contact low-pin-count serial interface using a single memory stack substrate assembly, and is therefore much smaller than earlier systems based on high-pin-count parallel interfaces using traditional surface-mount assembly such as [[CompactFlash]]. Both products were initially introduced using SanDisk [[NOR flash|NOR-based flash]] technology.

MMC is about the size of a postage stamp: 32&nbsp;mm&nbsp;× 24&nbsp;mm&nbsp;× 1.4&nbsp;mm.  MMC originally used a 1-[[bit]] [[serial interface]], but newer versions{{when|date=March 2018}} of the specification allow transfers of 4 or 8 bits at a time. MMC can be used in many devices that can use [[Secure Digital]] (SD) cards. MMCs may be available in sizes up to 16 [[gigabyte]]s (GB).

They are used in almost every context in which [[memory card]]s are used, like [[mobile phone|cellular phone]]s, digital audio players, [[Digital camera|digital cameras]], and [[Personal digital assistant|PDA]]s. Typically, an MMC operates as a storage medium for devices, in a form that can easily be removed for access by a [[Personal computer|PC]] via a connected MMC reader.

'''eMMC''' ([[embedded system|embedded]] MMC) is a small MMC chip used as [[Embedded system|embedded]] [[non-volatile memory]] that is normally soldered on [[printed circuit boards]], though pluggable eMMC modules are used on some devices (e.g. [[Orange Pi]] and [[ODROID]]).<ref>{{Cite web |last=Hunt |first=Cale |date=2023-02-06 |title=eMMC vs. SSD storage: What's the difference? |url=https://www.windowscentral.com/emmc-vs-ssd |url-status=live |archive-url=https://web.archive.org/web/20240218153058/https://www.windowscentral.com/emmc-vs-ssd |archive-date=2024-02-18 |access-date=2024-03-04 |website=Windows Central |language=en}}</ref><ref>{{Cite web |last=Ree |first=Brian |title=eMMC Memory Modules: A Simple Guide |url=https://magazine.odroid.com/article/emmc-memory-modules-a-simple-guide/ |url-status=live |archive-url=https://web.archive.org/web/20230921195144/https://magazine.odroid.com/article/emmc-memory-modules-a-simple-guide/ |archive-date=2023-09-21 |access-date=2024-03-04 |website=ODROID Magazine |language=en-US}}</ref><ref>{{Cite web |title=Orange Pi 32GB/64GB/256GB eMMC Module |url=http://www.orangepi.org/html/hardWare/computerAndMicrocontrollers/details/Orange-Pi-emmc.html |url-status=live |archive-url=https://web.archive.org/web/20240206002753/http://www.orangepi.org/html/hardWare/computerAndMicrocontrollers/details/Orange-Pi-emmc.html |archive-date=2024-02-06 |access-date=2024-03-04 |website=www.orangepi.org}}</ref>

== History ==
{{multiple image
 | align = right
 | direction = vertical
 | width = 
 | header = 
 | image1 = Four MMC cards front.jpg
 | alt1 = Front of four different MMC cards: MMC, RS-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
}}

The latest version of the eMMC standard ([https://www.jedec.org/standards-documents/docs/jesd84-b51 JESD84-B51]) by JEDEC is version 5.1A, released January 2019, with speeds (250&nbsp;MB/s read, 125&nbsp;MB/s write) rivaling discrete [[Serial ATA|SATA]]-based SSDs (500&nbsp;MB/s).<ref>{{cite web |title=e.MMC v5.1 |url=http://www.jedec.org/standards-documents/technology-focus-areas/flash-memory-ssds-ufs-emmc/e-mmc |access-date=2015-08-21 |publisher=JEDEC}}</ref>
[[File:MMC card vs SDHC card undersides angle.jpg|thumb|right|Undersides of an MMC (left) and SD card (right) showing the differences between the two formats]]

As of 23 September 2008, the [[MultimediaCard Association]] (MMCA) turned over all MMC specifications to the [[JEDEC|JEDEC organization]] including embedded MMC (eMMC), SecureMMC, and miCARD assets.<ref>{{Cite web |title=MultiMediaCard Association Merges with JEDEC {{!}} JEDEC |url=https://www.jedec.org/news/pressreleases/multimediacard-association-merges-jedec |access-date=2022-10-29 |website=www.jedec.org}}</ref> JEDEC is an organization devoted to standards for the solid-state industry.

The latest eMMC specifications can be requested from JEDEC, free-of-charge for JEDEC members.<ref>{{Cite web |title=Standards & Documents Search {{!}} JEDEC |url=https://www.jedec.org/document_search?search_api_views_fulltext=jesd84-b51 |access-date=2022-10-29 |website=www.jedec.org}}</ref> Older versions of the standard are freely available, but some optional enhancements to the standard such as MiCard and SecureMMC specifications, must be purchased separately. 

While there is no royalty charged for devices to host an MMC or eMMC, a royalty may be necessary in order to manufacture the cards themselves.

A highly detailed datasheet<ref>{{cite web |url=http://html.alldatasheet.com/html-pdf/141187/SAMSUNG/MC2GH512NMCA-2SA00/305/1/MC2GH512NMCA-2SA00.html |title=MC2GH512NMCA-2SA00 datasheet(1/102 Pages) SAMSUNG &#124; SAMSUNG MultiMediaCard |website=Html.AllDatasheet.com |date=2005-09-22 |access-date=2013-11-13}}</ref> that contains essential information for writing an MMC host driver is available online.

== Variants ==

=== RS-MMC ===

In 2004, the '''Reduced-Size MultiMediaCard''' ('''RS-MMC''') was introduced as a smaller form factor of the MMC, with about half the size: 24&nbsp;mm&nbsp;× 18&nbsp;mm&nbsp;× 1.4&nbsp;mm. The RS-MMC uses a simple mechanical adapter to elongate the card so it can be used in any MMC (or SD) slot. RS-MMCs are currently available in sizes up to and including 2&nbsp;GB.

The modern continuation of an RS-MMC is commonly known as '''MiniDrive''' ('''MD-MMC'''). A MiniDrive is generally a [[microSD]] card adapter in the RS-MMC form factor. This allows a user to take advantage of the wider range of modern MMCs available<ref>TheMiniDrive.com, http://www.TheMiniDrive.com. Extracted 23 April 2014.</ref> to exceed the historic 2&nbsp;GB limitations of older chip technology.

Implementations of RS-MMCs include [[Nokia]] and [[Siemens cellular telephones|Siemens]], who used RS-MMC in their [[Series 60]] [[Symbian]] [[smartphone]]s, the [[Nokia 770 Internet Tablet]], and generations 65 and 75 (Siemens). However, since 2006, all of Nokia's new devices with card slots have used [[miniSD]] or [[microSD]] cards, with the company dropping support for the MMC standard in its products. While Siemens exited the mobile phone business completely in 2006, the company continues to use MMC for some [[Programmable logic controller|PLC]] storage leveraging MD-MMC advances.

=== DV-MMC ===

The Dual-Voltage MultimediaCard ('''DV-MMC''') was one of the first changes in MMC.{{Citation needed|date=December 2022}} These cards can operate at 1.8&nbsp;V in addition to 3.3&nbsp;V. Running at lower voltages reduces the card's energy consumption, which is important in mobile devices. However, simple dual-voltage parts quickly went out of production in favor of MMCplus and MMCmobile, which offer capabilities in addition to dual-voltage capability.

=== MMCplus and MMCmobile ===
[[File:MMCplus and MMCmobile logo (recreated).png|thumb|Recreations of the MMCplus and MMCmobile logos]]

The version 4.x of the MMC standard, introduced in 2005, introduced two significant changes to compete against SD cards: (1) the ability to run at higher speeds (26&nbsp;MHz and 52&nbsp;MHz) than the original MMC (20&nbsp;MHz) or SD (25&nbsp;MHz, 50&nbsp;MHz), and (2) a four- or eight-bit-wide [[Bus (computing)|data bus]].

Version 4.x full-size cards and reduced-size cards can be marketed as '''MMCplus''' and '''MMCmobile''', respectively.

Version 4.x cards are fully backward compatible with existing readers but require updated hardware and software to use their new capabilities. Even though the four-bit-wide bus and high-speed modes of operation are deliberately electrically compatible with SD, the initialization protocol is different, so firmware and software updates are required to use these features in an SD reader.

=== MMCmicro ===
[[File:Mmc-micro.PNG|thumb|MMCmicro]]

'''MMCmicro''' is a smaller version of MMC. With dimensions of 14&nbsp;mm&nbsp;× 12&nbsp;mm&nbsp;× 1.1&nbsp;mm, it is smaller and thinner than RS-MMC. Like MMCmobile, MMCmicro allows dual voltage, is backward compatible with MMC, and can be used in full-size MMC and SD slots with a mechanical adapter. MMCmicro cards have the high-speed and four-bit-bus features of the 4.x spec, but not the eight-bit bus, due to the absence of the extra pins.<ref>{{cite web|url=http://www.samsung.com/Products/Semiconductor/FlashCard/MMC/micro_mmc.htm |title=Samsung Semiconductor Global Official Website |language=ru |publisher=Samsung.com |access-date=2013-11-13}}</ref>

This variant was formerly known as ''S-card'' when introduced by [[Samsung]] on 13 December 2004. It was later adapted and introduced in 2005 by the MultiMediaCard Association (MMCA) as the third form factor memory card in the ''MultiMediaCard'' family.<ref>allmemorycards.com, ''[http://www.allmemorycards.com/mmc-micro.htm MMCmicro]''. Extracted 22 April 2006.</ref>

MMCmicro appears very similar to [[microSD]], but the two formats are not physically compatible and have incompatible pinouts.

=== MiCard ===

The '''MiCard''' is a backward-compatible extension of the MMC standard with a theoretical maximum size of 2048&nbsp;GB (2 terabytes) announced on 2 June 2007. The card is composed of two detachable parts, much like a microSD card with an SD adapter. The small memory card fits directly in a USB port and has MMC-compatible electrical contacts. With an included electromechanical adapter, it can also fit in traditional MMC and SD card readers. To date, only one manufacturer (Pretec) has produced cards in this format.<ref name=micard>{{ cite web | title = Pretec Announces S-Diamond, 1st in the World to Implement miCARD Standard | url = http://www.businesswire.com/portal/site/google/index.jsp?ndmViewId=news_view&newsId=20070604006489&newsLang=en | access-date = 21 January 2010 }}</ref>

The MiCard was developed by the [[Industrial Technology Research Institute]] in [[Taiwan]]. At the time of the announcement, twelve Taiwanese companies (including [[ADATA]] Technology, [[Asustek]], [[BenQ]], [[Carry Computer Eng. Co.]], [[C-One Technology]], [[DBTel]], [[Power Digital Card Co.]], and [[RiCHIP]]) had signed on to manufacture the new memory card. However, as of June 2011, none of the listed companies had released any such cards, nor had any further announcements been made about plans for the format.

The card was announced to be available starting in the third quarter of 2007. It was expected to save the 12 Taiwanese companies who planned to manufacture the product and related hardware up to US$40 million in licensing fees, which presumably would otherwise be paid to owners of competing flash memory formats. The initial card was to have a capacity of 8&nbsp;GB, while the standard would allow sizes up to 2048&nbsp;GB. It was stated to have data transfer speeds of 480&nbsp;[[Mbit/s]] (60&nbsp;[[Mbyte/s]]), with plans to increase data over time.

=== eMMC ===
[[File:Samsung Galaxy Tab 2 10.1 - Samsung KLMAG2GE4A-A002-3955.jpg|thumb|eMMC KLMAG2GE4A-A002 inside the [[Samsung Galaxy Tab 2 10.1]]]]

The currently implemented '''embedded MMC'''<ref>{{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}}</ref> ('''eMMC''' or '''{{notatypo|e.MMC}}''') architecture puts the MMC components (flash memory, buffer and controller) into a small [[ball grid array]] (BGA) IC package for use in circuit boards as an embedded non-volatile memory system. This is noticeably different from other versions of MMC as this is not a user-removable card, but rather a permanent attachment to the [[printed circuit board]] (PCB). Therefore, in the event of an issue with either the memory or its controller, the eMMC would need to be replaced or repaired. In eMMC, the host system simply reads and writes data to and from the [[Logical block addressing|logical block addresses]]. The eMMC controller hardware and firmware lifts the burden on the host system by performing error correction and data management. eMMC exists in 100, 153, and 169 ball packages and is based on an 8-bit parallel interface.<ref>{{cite web |url=https://www.hyperstone.com/en/Registration-Hyperstone-1125.html |url-access=registration |title=Flash Memory Form Factors |author=<!--Not stated--> |series=The Fundamentals of Reliable Flash Storage |publisher=Hyperstone GmbH |access-date=19 April 2018}}</ref>

Almost all mobile phones and tablets used this form of flash for main storage until 2016, when [[Universal Flash Storage]] (UFS) started to take control of the market. However, as of 2023, eMMC is still used in many consumer applications, including lower-end smartphones, such that [[Kioxia]] has introduced new 64&nbsp;GB and 128&nbsp;GB eMMC 5.1 modules based on modern [[3D NAND]] flash scheduled for mass production in 2024.<ref>{{Cite web |date=2023-09-27 |title=KIOXIA Introduces Next Generation e-MMC Ver. 5.1-Compliant Embedded Flash Memory Products |url=https://www.businesswire.com/news/home/20230927535891/en/KIOXIA-Introduces-Next-Generation-e-MMC-Ver.-5.1-Compliant-Embedded-Flash-Memory-Products |access-date=2023-09-28 |website=www.businesswire.com |language=en}}</ref><ref>{{Cite web |last=Shilov |first=Anton |title=eMMC Destined to Live a Bit Longer: KIOXIA Releases New Generation of eMMC Modules |url=https://www.anandtech.com/show/21074/emmc-to-live-a-bit-longer-kioxia-releases-new-emmc-products |access-date=2023-09-28 |website=www.anandtech.com}}</ref> 

eMMC does not support the [[Serial Peripheral Interface|SPI-bus]] protocol and uses NAND flash.<ref>{{Cite web |date=6 September 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/}}</ref>
{| class="wikitable"
|+ eMMC versions
! Version
! Sequential read (MB/s)
! Sequential write (MB/s)
! Random read (IO/s)
! Random write (IO/s)
! Clock frequency (MHz)
! Used in
|-
! 4.3
|
|
|
|
|
|
|-
! 4.4
|
|
|
|
|
|
|-
! 4.41
|
|
|
|
| 52<ref>{{Cite web |last1=Moon |first1=Yejin |date=2014-03-20 |orig-date=Presented in November 2011 |title=Q4.11: Introduction to eMMC |url=https://www.slideshare.net/linaroorg/intro-to-emmc}}</ref>
|
|-
! 4.5
| 140<ref>{{Cite web |title=eMMC to UFS: How NAND Memory for Mobile Products Is Evolving |url=https://news.samsung.com/global/emmc-to-ufs-how-nand-memory-for-mobile-products-is-evolving |access-date=2021-02-16 |website=news.samsung.com |language=en}}</ref>
| 50
| 7000
| 2000
| 200
| [[Snapdragon 800]]
|-
! 5.0
| 250
| 90
| 7000
| 13000
|
| Snapdragon 801
|-
! 5.1
| 250
| 125
| 11000
| 13000
|
| Snapdragon 820
|} <!--does repair mean replacing the emmc itself?-->

== Uses ==

Modern computers, both laptops and desktops, often have SD slots, which can additionally read MMCs if the operating system drivers can. Since the introduction of SD cards, few companies build MMC slots into their devices (an exception is some mobile devices like the [[Nokia 9300]] communicator in 2004, where the smaller size of the MMC is a benefit), but the slightly thinner, pin-compatible MMCs can be used in almost any device that can use SD cards if the software/firmware on the device is capable.

While few companies build MMC slots into devices {{as of | 2018 | lc = on}}, due to SD cards dominating the [[memory card]] market, the embedded MMC ({{notatypo|e.MMC}}) is still widely used in consumer electronics as a primary means of integrated storage and [[boot loader]] in portable devices. eMMC provides a low-cost<ref>{{Cite web |title=eMMC Chips |url=https://www.mouser.com/c/semiconductors/memory-ics/emmc/?sort=pricing}}</ref> flash-memory system with a built-in controller that can reside inside an [[Android (operating system)|Android]] or [[Microsoft Windows|Windows]] phone or in a low-cost PC and can appear to its host as a bootable device, in lieu of a more expensive form of solid-state storage, such as a traditional [[solid-state drive]].

== Similar formats ==

In 2004, a group of companies—including [[Seagate Technology|Seagate]] and [[Hitachi]]—introduced an interface called [[CE-ATA]] for [[Small Form Factor committee|small form factor]] hard disk drives.<ref>{{cite web |title=New Consumer Electronic Interface on Future Hard Drives |url=https://phys.org/news/2004-09-consumer-electronic-interface-future-hard.html |website=Phys.org |access-date=1 April 2019}}</ref> This interface was electrically and physically compatible with the MMC specification. However, support for further development of the standard ended in 2008.<ref>{{cite web |title=Consumer Electronics ATA (CE-ATA) |url=https://www.techopedia.com/definition/26017/consumer-electronics-ata-ce-ata |website=Technopedia |access-date=1 April 2019}}</ref>

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.<ref name="vitadump">{{Cite web |last=wololo |date=2016-08-25 |title=Playstation Vita Cartridge Dump explained |url=https://wololo.net/2016/08/25/playstation-vita-cartridge-dump-explained/ |access-date=2022-07-29 |website=Wololo.net |language=en-US}}</ref>

== See also ==

* [[Comparison of memory cards]]
* [[Universal Flash Storage]]

==References==
{{refs}}

== External links ==
{{commonscat|Multi Media Card}}

* [http://www.jedec.org/ JEDEC] – Solid State Technology Association
* {{webarchive|url=https://web.archive.org/web/20070126005916/https://www.sandisk.com/Assets/File/OEM/Manuals/ProdManRS-MMCv1.3.pdf|title=SanDisk MultiMediaCard and Reduced-Size MultiMediaCard Product Manual}}
* {{webarchive|url=https://web.archive.org/web/20071010143502/http://www.kingmaxdigi.com/product/MMC.pdf|title=KingMax Digital Inc. MMC Card Specification}}
* [http://www.hardwarebook.info/MMC MMC pinout (tech.)]
* [http://www.hardwarebook.info/MMCplus MMCplus pinout (tech.)]

{{Memory Cards}}

{{Use dmy dates|date=August 2021}}
[[Category:Open standards]]
[[Category:Sandisk]]
[[Category:Siemens]]
[[Category:Computer-related introductions in 1997]]
[[Category:Solid-state computer storage]]