| MultiMediaCard | |
A 32 MB MultiMediaCard
|
|
| Capacity | up to 4 GB (current maximum sold) |
|---|---|
| Developed by | Siemens AG and SanDisk |
The MultiMediaCard (MMC) is a flash memory memory card standard. A megabyte is a unit of Information or Computer storage equal to either 106 (1000000 Bytes or 220 (1048576 bytes depending on SanDisk Corporation ( is an American Multinational corporation which designs and markets Flash memory card products A megabyte is a unit of Information or Computer storage equal to either 106 (1000000 Bytes or 220 (1048576 bytes depending on Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed A memory card or flash memory card is a solid-state electronic Flash memory Data storage device used with Digital Unveiled in 1997 by Siemens AG and SanDisk, it is based on Toshiba's NAND-based flash memory, and is therefore much smaller than earlier systems based on Intel NOR-based memory such as CompactFlash. Year 1997 ( MCMXCVII) was a Common year starting on Wednesday (link will display full 1997 Gregorian calendar SanDisk Corporation ( is an American Multinational corporation which designs and markets Flash memory card products ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed CompactFlash ( CF) is a Mass storage device format used in portable electronic devices MMC is about the size of a postage stamp: 24 mm x 32 mm x 1. 4 mm. MMC originally used a 1-bit serial interface, but newer versions of the specification allow transfers of 4 or sometimes even 8 bits at a time. A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication In Telecommunication and Computer science, serial communication is the process of sending data one Bit at one time sequentially over a Communication They have been more or less superseded by Secure Digital cards (SD card), but still see significant use because MMCs can be used in most devices which support SD cards. Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in
Typically, an MMC is used as storage media for a portable device, in a form that can easily be removed for access by a PC. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated For example, a digital camera would use an MMC for storing image files. Many compact digital still cameras can record Sound and moving Video as well as still Photograph. With an MMC reader (typically a small box that connects via USB or some other serial connection, although some can be found integrated into the computer itself), a user could copy the pictures taken with the digital camera off to his or her computer. Modern computers, both laptops and desktops, often have SD slots, which can additionally read MMCs if the operating system drivers support them.
MMCs are currently available in sizes up to and including 4 GB with 8 GB models announced but not yet available. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer They are used in almost every context in which memory cards are used, like cellular phones, digital audio players, digital cameras and PDAs. A memory card or flash memory card is a solid-state electronic Flash memory Data storage device used with Digital A digital audio player, more commonly referred to as an MP3 player, is a Consumer electronics device that stores organizes and plays audio files Some Many compact digital still cameras can record Sound and moving Video as well as still Photograph. Since the introduction of Secure Digital card and SDIO (Secure Digital Input/Output) slot few companies build MMC slots into their devices (an exception is some mobile devices like the Nokia 9300 communicator, 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 supports SD cards if the software/firmware on the devices support them. Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in The Nokia 9300 is a Nokia Series 80 Symbian Smartphone. It is used as a normal though bulky mobile phone in closed mode when it is flipped open it
Contents |
Open standard
This technology is a standard available to any company wanting to develop products based on it. Generally a company is a form of Business organization. The precise definition varies The specification is not free - it must be purchased from the MMC Association[1] who impose considerable restrictions on how the specification can be used. [2]
As of February 2008, the specifications version 4. 3 (dated nov 2007) can be requested from the MMCA, and after registering downloaded free-of-charge.
Samsung, a major backer of MMC, provides a highly detailed datasheet[3] which contains much of the essential information for writing an MMC driver. The Samsung Group ( Korean:, Samsung Guerup) is South Korea 's largest company or Chaebol and the world's largest conglomerate
Variants
Reduced-Size MultiMediaCard (RS-MMC)
MMCs also come in a smaller form factor, of about half the size: 24 mm × 18 mm × 1. 4 mm. This alternate form factor is known as Reduced-Size MultiMediaCard, or RS-MMC, and was introduced in 2004. "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " RS-MMCs are simply smaller MMCs; by using a simple mechanical adapter to elongate the card, an RS-MMC can be used in any MMC (or SD) slot. RS-MMCs are currently available in sizes up to and including 2 GB. A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer
The only significant hardware licensors of RS-MMCs were Nokia and Siemens, who used to use RS-MMC in their Series 60 Symbian smartphones, the Nokia 770 Internet Tablet , and generations 65 and 75 (Siemens). Nokia Corporation (pronunciation /'nɔkiɑ/),,) is a Finnish multinational Communications Corporation, headquartered Siemens cellular telephones are mobile phones produced by Siemens AG. The S60 Platform (formerly Series 60 User Interface is a software platform for Mobile phones that runs on Symbian OS. Symbian OS is an open Operating system, designed for Mobile devices with associated libraries, User interface frameworks and A smartphone is a Mobile phone offering advanced capabilities beyond a typical mobile phone often with PC -like functionality The Nokia 770 Internet Tablet is a wireless Internet appliance from Nokia, originally announced at the LinuxWorld Summit in New York City on However, since 2006 all of Nokia's new devices with card slots have used miniSD or microSD cards, with the company appearing to abandon the MMC standard in its products. The miniSD Card is a small Form factor removable and portable memory device intended for use in cell phones / mobile phones, digital cameras microSD is a format for removable Flash memory cards It is derived from SanDisk TransFlash and is used mainly in mobile Siemens exited the mobile phone business completely in 2006.
Dual-Voltage MultimediaCard (DV-MMC)
One of the first substantial changes in MMC was the introduction of dual-voltage cards that support operations at 1. 8 V in addition to 3. 3 V. Running at lower voltages reduces the card's power consumption, which is important in mobile devices. However, simple dual-voltage parts quickly went out of production in favour of MMCplus and MMCmobile which offer additional capabilities on top of dual-voltage support.
MMCplus and MMCmobile
The version 4. x of the MMC standard, introduced in 2005, brought in two very significant changes to compete against SD cards. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. These were support for running at higher speeds (26MHz, 52MHz) than the original MMC (20MHz) or SD (25MHz, 50MHz) and 4 or 8 bit wide data buses.
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/software to use their new capabilities; even though the 4 bit wide bus and high-speed modes of operation are deliberately electrically compatible with SD, the initialization protocol is different, so firmware/software updates are required to allow these features to be enabled when the card is used in an SD reader.
MMCmicro
MMCmicro is a micro-size version of MMC. With dimensions of 14 mm × 12 mm × 1. 1 mm, it is even smaller and thinner than RS-MMC. Like MMCmobile, MMCmicro supports dual voltage, is backward compatible with MMC, and can be used in full-size MMC and SD slots with a mechanical adapter. MMCmicro cards support the high-speed and 4 bit bus features of the 4. x spec, but not the 8 bit bus, due to the absence of the extra pins[4]
MMCmicro cards appears very similar to microSD but the two formats are not physically compatible and have irreconcilable pinouts. microSD is a format for removable Flash memory cards It is derived from SanDisk TransFlash and is used mainly in mobile
MiCard
The MiCard is a backward-compatible extension of the MMC standard with a theoretical maximum size of 2048 GB (2 TB) announced in 2007. The miCard (Multiple Interface card is a type of flash Memory card that is compatible with existing USB Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The card is comprised of two detachable parts, much like RS-MMC. The smaller card fits in a USB port while the larger version fits in traditional MMC and SD card readers.
SecureMMC
An additional, optional, part of the MMC 4. x specification is a DRM mechanism intended to enable MMC to compete with SD or Memory Stick in this area. Memory Stick is a removable flash Memory card format launched by Sony in October 1998, and is also used in general to describe the whole family Very little information is known about how SecureMMC works or how its DRM characteristics compare with its competitors.
Others
Seagate, Hitachi and others are in the process of releasing SFF Hard Disk drives with an interface called CE-ATA. The Small Form Factor committee is an ad hoc Electronics industry group formed to quickly develop interoperability specifications (as a compliment to the traditional standards This interface is electrically and physically compatible with MMC specification. However, the command structure has been expanded to allow the host controller to issue ATA commands to control the hard disk drive. AT Attachment with Packet Interface ( ATA/ATAPI) is a standard interface used to connect storage devices such as Hard disks Solid-state
Comparisons
| Type | MMC | RS-MMC | MMC Plus | SecureMMC | SD | SDIO | miniSD | microSD |
|---|---|---|---|---|---|---|---|---|
| SD Socket | Yes | Mechanical adapter | Yes | Yes | Yes | Yes | Electro-mechanical adapter | Electro-mechanical adapter |
| Pins | 7 | 7 | 13 | 7 | 9 | 9 | 11 | 8 |
| Form factor | Thin | Thin/short | Thin | Thin | Thick (exceptions possible) | Thick | Narrow/short/thin | Narrow/short/extra thin |
| Width | 24 mm | 24 mm | 24 mm | 24 mm | 24 mm | 24 mm | 20 mm | 11 mm |
| Length | 32 mm | 18 mm | 32 mm | 32 mm | 32 mm | 32 mm+ | 21. The MultiMediaCard ( MMC) is a Flash memory The MultiMediaCard ( MMC) is a Flash memory The MultiMediaCard ( MMC) is a Flash memory Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in The miniSD Card is a small Form factor removable and portable memory device intended for use in cell phones / mobile phones, digital cameras microSD is a format for removable Flash memory cards It is derived from SanDisk TransFlash and is used mainly in mobile 5 mm | 15 mm |
| Thickness | 1. 4 mm | 1. 4 mm | 1. 4 mm | 1. 4 mm | 2. 1 mm (exceptions possible) | 2. 1 mm | 1. 4 mm | 1 mm |
| SPI mode | Optional | Optional | Optional | Required | Required | Required | Required | Optional |
| 1 bit mode | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 4 bit mode | No | No | Yes | ? | Optional | Optional | Optional | Optional |
| 8 bit mode | No | No | Yes | ? | No | No | No | No |
| interrupts | No | No | No | No | No | Optional | No | No |
| Xfer clock | 0–20 MHz | 0–20 MHz | 0–52 MHz | 0–20 MHz? | 0–25 MHz - 0–50 MHz | 0–25 MHz | 0–25 MHz? | 0–25 MHz? |
| Max Transfer | 20 Mbit/s | 20 Mbit/s | 416 Mbit/s | 20 Mbit/s? | 100 Mbit/s - 200 Mbit/s | 100 Mbit/s | 100 Mbit/s | 100 Mbit/s |
| Max SPI Transfer | 20 Mbit/s | 20 Mbit/s | 52 Mbit/s | 20 Mbit/s | 25 Mbit/s | 25 Mbit/s | 25 Mbit/s | 25 Mbit/s |
| DRM | No | No | No | Yes | Yes | N/A | Yes | Yes |
| User encrypt | No | No | No | Yes | No | No | No | No |
| Simplified Spec | Yes | Yes | No | Not yet? | Yes | Yes | No | No |
| Memb cost | $2500/yr (not required) | $2000/yr (General), $4500/yr (Executive) | ||||||
| Spec cost | $500 | ? | ? | Member | Member | Member | Member | |
| Host license | No | No | No | No | $1000/yr + membership cost | |||
| Mem card royalties | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| I/O card royalties | N/A | N/A | N/A | N/A | N/A | $1000/yr + membership cost | N/A | N/A |
| Open source compatible | Yes | Yes | Yes? | Yes? | Yes | Yes | Yes | Yes |
| Type | MMC | RS-MMC | MMC Plus | SecureMMC | SD | SDIO | miniSD | microSD |
Table data compiled mostly from simplified versions of MMC and SDIO specifications and other data on SD card and MMC association web sites. Interface The SPI bus specifies four logic signals SCLK &mdash Serial Clock (output from master MOSI/SIMO &mdash Master Output Slave Input (output A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) Interface The SPI bus specifies four logic signals SCLK &mdash Serial Clock (output from master MOSI/SIMO &mdash Master Output Slave Input (output Digital rights management ( DRM) is a generic term that refers to Access control technologies used by hardware manufacturers publishers and Copyright holders Data for other card variations is interpolated.
Capacity limit in all SD/MMC formats appears to be 128 GB in LBA mode (28-bit sector address). A gigabyte (derived from the SI prefix Giga-) is a unit of Information or Computer Logical block addressing (LBA is a common scheme used for specifying the location of blocks of data stored on Computer storage devices generally Secondary storage
See also
External links
- MultiMediaCard Association
- Sandisk OEM Manual for MMC and RS-MMC (PDF)
- KingMax MMC technical document (PDF)
- MMC pinout (tech.)
- MMCplus pinout (tech.)
References
- ^ MMCA: Specification for Non-Members, www. This table provides summary of comparison of various flash Memory cards As of 2008. Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in mmca. org, 2007
- ^ Product Information and License Agreement, www. mmca. org, 2007
- ^ Samsung MMC Datasheet, http://www.samsung.com 2007
- ^ Samsung's MMCmicro description, http://www.samsung.com 2007
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic