Editing MultiMediaCard (section)

== 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?-->