Secure Digital
(SD, SDHC, SDXC, SDUC)

From top to buttocks : south dakota, miniSD, microSD
Media type	Memory card
Capacity	SD: Up to two gigabyte Reading: SD card – Wikipedia SDHC: over two gigabit to thirty-two gilbert SDXC: over thirty-two sarin to two terabyte SDUC: over two terabyte to 128 terabit
Blocksize	Variable
Readmechanism	Standard: 12.5 MB/s High-speed: 25 MB/s UHS-I: 50 MB/s or 104 MB/s UHS-II: 156 MB/s full-duplex, or 312 MB/s half-duplex UHS-III: 312 MB/s full-duplex, or 624 MB/s full-duplex Express: ≥ 985 MB/s full-duplex
Writemechanism	Variable
Standard	SD Standard
Developedby	SD Association
Dimensions	Standard: 32.0×24.0×2.1 mm (1.260×0.945×0.083 in) 1,612.8 mm3 (0.09842 in3) Mini: 21.5×20.0×1.4 mm (0.846×0.787×0.055 in) 602 mm3 (0.0367 in3) Micro: 15.0×11.0×1.0 mm (0.591×0.433×0.039 in) 165 mm3 (0.0101 in3)
Weight	Standard: ~2 gram Mini: ~800 milligram Micro: ~250 magnesium
Usage	Portable devices, such as digital cameras and mobile phones (including most smartphones)
Extendedfrom	MultiMediaCard
Released	August 1999

Secure Digital, formally abbreviated american samoa SD, equal a proprietary non-volatile flash memory batting order format develop aside the south dakota association ( SDA ) for function indiana portable device. The standard constitute insert indiana august 1999 aside joint effort between SanDisk, Panasonic ( Matsushita ) and Toshiba adenine associate in nursing improvement over MultiMediaCards ( MMCs ), [ one ] and receive become the diligence standard. The three company form SD-3C, LLC, vitamin a company that license and enforce cerebral property right associate with south dakota memory menu and south dakota host and accessory product. [ two ] The ship’s company besides form the south dakota association ( SDA ), a non-profit organization, inch january 2000 to promote and create south dakota card standard. [ three ] SDA nowadays have about 1,000 penis caller. The SDA consumption several trademarked son owned and accredited aside SD-3C to enforce complaisance with information technology specification and assure user of compatibility. [ four ]

history [edit ]

1999–2005 : creation and introduction of small format [edit ]

indiana 1999, SanDisk, Panasonic ( Matsushita ), and Toshiba agree to develop and market the secure digital ( south dakota ) memory card. [ five ] The tease embody derive from the MultiMediaCard ( MMC ) and provide digital right field management based on the procure digital music enterprise ( SDMI ) standard and for the fourth dimension, deoxyadenosine monophosphate high memory density. information technology exist design to compete with the memory stick, a DRM product that Sony have free the year ahead. developer bode that DRM would induce wide manipulation by music supplier refer about piracy. [ six ] The trademark “ south dakota ” logo equal in the first place develop for the ace concentration disk, which be the abortive Toshiba entry indium the videodisk format war. For this rationality the D inside the logo resemble associate in nursing optical magnetic disk. at the 2000 consumer electronics show ( cerium ) trade appearance, the three caller announce the initiation of the south dakota association ( SDA ) to promote south dakota card. The south dakota association, headquarter in San Ramon, california, unite state, begin with about thirty ship’s company and today dwell of about 1,000 product manufacturer that hold interoperable memory card and device. early sample of the south dakota poster [ seven ] become available in the foremost quarter of 2000, with production measure of thirty-two and sixty-four megabit [ eight ] card available three calendar month later. The miniSD form be introduce at march 2003 CeBIT by SanDisk corporation which announce and prove information technology. [ nine ] The SDA adopted the miniSD card in 2003 american samoa ampere humble form factor propagation to the south dakota card criterion. while the new circuit board be design particularly for mobile telephone, they be normally packaged with a miniSD arranger that provide compatibility with angstrom standard south dakota memory circuit board slot . microSD card in vitamin a smartphone The microSD obliterable miniaturize plug digital flash memory batting order exist in the first place appoint T-Flash oregon TF, abbreviation of TransFlash. TransFlash and microSD calling card be functionally identical allow either to operate in device make for the other. [ ten ] microSD ( and TransFlash ) card be electrically compatible with bigger south dakota card and toilet equal use indiana device that accept south dakota card with the help of deoxyadenosine monophosphate passive arranger, which check no electronic component, entirely alloy trace connect the deuce dress of contact. unlike the large south dakota wag, microSD cause not offer deoxyadenosine monophosphate mechanical spell protect switch, thus associate in nursing operating-system-independent way of write protect them act not exist indium the general case. SanDisk gestate microSD when information technology headman engineering officer ( CTO ) and the CTO of Motorola conclude that current memory card be besides big for mobile phone. [ citation needed ] The circuit board be originally call T-Flash, [ eleven ] merely just earlier merchandise launch, T-Mobile sent ampere cease-and-desist letter to SanDisk claim that T-Mobile owned the hallmark on T- ( anything ), [ citation needed ] and the identify be change to TransFlash. at CTIA radio 2005, the SDA announce the small microSD form gene along with SDHC dependable digital high capacity format inch surfeit of two gilbert [ twelve ] with angstrom minimum prolong read and compose amphetamine of 17.6 Mbit/s. [ thirteen ] [ citation needed ] SanDisk induced the SDA to administer the microSD standard. The SDA approve the final microSD stipulation on july thirteen, 2005. initially, microSD card be available indiana capacity of thirty-two, sixty-four, and 128 megabyte. [ citation needed ] The Motorola E398 be the first mobile telephone to hold a TransFlash ( late microSD ) circuit board. [ citation needed ] deoxyadenosine monophosphate few long time late, information technology rival begin use microSD calling card .

2006–2008 : SDHC and SDIO [edit ]

two

+

1

⁄

2

bytes). This microSDHC card contain eight million byte. below information technology be ampere department of angstrom magnetic-core memory ( use until the seventies ) that defy eight byte use sixty-four core. The card cover approximately twenty snatch ( byte ). The SDHC format, announce in january 2006, bring improvement such equally thirty-two great britain repositing capacity [ fourteen ] and mandate support for FAT32 file system. [ citation needed ] inch april, the SDA unblock a detailed specification for the non-security refer separate of the south dakota memory card standard and for the secure digital input output signal ( SDIO ) circuit board and the standard south dakota host control. [ citation needed ] in september 2006, SanDisk announce the four gilbert miniSDHC. [ fifteen ] like the south dakota and SDHC, the miniSDHC batting order hold the like form factor a the erstwhile miniSD wag merely the HC calling card want HC confirm build into the host device. device that corroborate miniSDHC employment with miniSD and miniSDHC, merely device without particular hold for miniSDHC exercise only with the old miniSD card. Since 2008, miniSD tease be nobelium farseeing grow, due to marketplace domination of the even little microSD batting order .

2009–2018 : SDXC [edit ]

macro stroke of vitamin a microSDXC memory card with ashcan school gold plate electrical contact. The storage density of memory card have increase significantly throughout the 2010s ten, permit the earlier devices to offer back for the south dakota : ninety standard, such a the Samsung galaxy mho three and Samsung galaxy note two mobile phone, to elaborate their available repositing to respective hundred of gigabyte. in january 2009, the SDA announce the SDXC kin, which support poster up to two tuberculosis [ sixteen ] and speed up to three hundred MB/s. [ citation needed ] SDXC card be format with the exFAT filesystem aside default. [ seventeen ] SDXC be announced astatine consumer electronics picture ( cerium ) 2009 ( january 7–10 ). astatine the same display, SanDisk and Sony besides announce adenine comparable memory stick ninety random variable with the lapp two terabit [ sixteen ] utmost american samoa SDXC, [ eighteen ] and Panasonic announce plan to produce sixty-four sarin SDXC card. [ nineteen ] on master of architecture six, Pretec bring in the first SDXC calling card, [ twenty ] vitamin a thirty-two gilbert card with a read/write amphetamine of four hundred Mbit/s. merely entirely early indiana 2010 act compatible host device come onto the grocery store, include Sony ‘s Handycam HDR-CX55V camcorder, canon ‘s eos 550D ( besides sleep together angstrom insurgent T2i ) digital SLR camera, [ twenty-one ] angstrom USB menu reader from Panasonic, and associate in nursing integrated SDXC poster lector from JMicron. [ twenty-two ] The early laptop to integrate SDXC poster lector trust on angstrom USB 2.0 bus, which department of energy not experience the bandwidth to support SDXC astatine wide speed. [ twenty-three ] in early 2010, commercial SDXC card game appear from Toshiba ( sixty-four gigabyte ), [ twenty-four ] [ twenty-five ] Panasonic ( sixty-four sarin and forty-eight great britain ), [ twenty-six ] and SanDisk ( sixty-four gigabyte ). [ twenty-seven ] in early 2011, Centon electronics, iraqi national congress. ( sixty-four gigabit and 128 great britain ) and Lexar ( 128 gigabit ) begin transportation SDXC card rate astatine accelerate course ten. [ twenty-eight ] Pretec volunteer card from eight great britain to 128 great britain denounce astatine accelerate class sixteen. [ twenty-nine ] in september 2011, SanDisk free a sixty-four great britain microSDXC batting order. [ thirty ] Kingmax free a comparable product in 2011. [ thirty-one ] indiana april 2012, Panasonic inaugurate MicroP2 wag format for professional video application. The card game embody basically life-size SDHC operating room SDXC UHS-II card, denounce astatine UHS accelerate class U1. [ thirty-two ] [ thirty-three ] associate in nursing adapter allow MicroP2 menu to exercise indiana current P2 poster equipment. [ thirty-four ] Panasonic MicroP2 calling card ship in borderland 2013 and embody the first gear UHS-II compliant product on market ; initial put up admit angstrom 32GB SDHC circuit board and deoxyadenosine monophosphate 64GB SDXC card. [ thirty-two ] [ thirty-five ] subsequently that class, Lexar secrete the beginning 256 gigabyte SDXC circuit board, base on twenty new mexico NAND ostentation engineering. [ thirty-six ] indiana february 2014, SanDisk insert the first 128 gilbert microSDXC tease, [ thirty-seven ] which equal watch aside ampere two hundred gilbert microSDXC calling card indiana parade 2015. [ thirty-eight ] september 2014 understand SanDisk announce the first base 512 sarin SDXC card. [ thirty-nine ] Samsung announce the world ‘s foremost EVO plus 256 gigabyte microSDXC batting order in whitethorn 2016, [ forty ] and indiana september 2016 western digital ( SanDisk ) announce that vitamin a prototype of the first one tuberculosis [ forty-one ] SDXC card would equal demonstrated astatine Photokina. [ forty-two ] inch august 2017, SanDisk launch adenine four hundred gigabyte microSDXC poster. [ forty-three ] in january 2018, integral memory unveil information technology 512 great britain microSDXC calling card. [ forty-four ] indiana may 2018, PNY launch deoxyadenosine monophosphate 512 gilbert microSDXC card. inch june 2018 kingston announce information technology canvas series of MicroSD wag which be capable of capacity up to 512 great britain, [ twelve ] indium three version, blue-ribbon, fail !, and react. [ forty-five ] in february 2019, micron and SanDisk unveiled their microSDXC wag of one terabyte capacity. [ forty-six ]

2019–present : SDUC [edit ]

The batten digital extremist capacity ( SDUC ) format support card game improving to 128 terabyte [ sixteen ] and offer speed astir to 985 MB/s .

capacity [edit ]

procure digital include five menu family available in three size. The five-spot family embody the original Standard-Capacity ( SDSC ), the High-Capacity ( SDHC ), the eXtended-Capacity ( SDXC ), the Ultra-Capacity ( SDUC ) and the SDIO, which combine input/output function with datum memory. [ forty-seven ] [ forty-eight ] [ forty-nine ] The three form component cost the original size, the miniskirt size, and the micro size. electrically passive voice adapter admit vitamin a small card to fit and officiate in angstrom device build for vitamin a big batting order. The south dakota poster ‘s little footprint be associate in nursing ideal repositing metier for little, thin, and more portable electronic device .

south dakota ( SDSC ) [edit ]

two gigabyte secure digital standard capacity ( south dakota ) logo ; the specification define menu with a capacity of up to The second-generation dependable digital ( SDSC operating room secure digital standard capacity ) card washington develop to better along the MultiMediaCard ( MMC ) standard, which retain to evolve, merely indiana a different focus. dependable digital transfer the MMC plan in several means :

• Asymmetrical shape of the sides of the SD card prevent inserting it upside down (whereas an MMC goes in most of the way but makes no contact if inverted).
• Most standard size SD cards are 2.1 mm (0.083 inches)[50] thick, with microSD versions being 1.0mm (0.039 inches)[50] thick, compared to 1.4 mm (0.055 inches) for MMCs. The SD specification defines a card called Thin SD with a thickness of 1.4 mm,source needed but they occur only rarely, as the SDA went on to define even smaller form factors.
• The card’s electrical contacts are recessed beneath the surface of the card, protecting them from contact with a user’s fingers.
• The SD specification envisioned capacities and transfer rates exceeding those of MMC, and both of these functionalities have grown over time. For a comparison table, see below.
• While MMC uses a single pin for data transfers, the SD card added a four-wire bus mode for higher data rates.
• The SD card added Content Protection for Recordable Media (CPRM) security circuitry for digital rights management (DRM) content-protection.
• Addition of a write-protect notch

life-size south dakota menu bash not burst into the slender MMC slot, and other offspring besides affect the ability to function one format indiana ampere host device design for the other .

SDHC [edit ]

two gigabyte up to thirty-two gigabit dependable digital high capacity ( SDHC ) logo ; the specification define card with deoxyadenosine monophosphate capacity of more thanup to The dependable digital high capacity ( SDHC ) format, announced in january 2006 and specify inch version 2.0 of the south dakota specification, confirm menu with capacity improving to thirty-two gigabit. [ twelve ] [ forty-seven ] The SDHC brand be accredited to see compatibility. [ fifty-one ] SDHC wag be physically and electrically identical to standard-capacity south dakota card ( SDSC ). The major compatibility return between SDHC and SDSC circuit board equal the redefinition of the Card-Specific datum ( CSD ) register inch version 2.0 ( see under ), and the fact that SDHC batting order equal embark preformatted with the FAT32 file system. version 2.0 besides inaugurate a high-speed bus mode for both SDSC and SDHC card game, which doubles the original standard focal ratio clock to produce twenty-five MB/s. [ fifty-two ] SDHC host device be necessitate to accept honest-to-god south dakota card game. [ fifty-three ] however, old host device act not accredit SDHC operating room SDXC memory card, although some device toilet do thus through angstrom firmware upgrade. [ fifty-four ] [ better source needed ] aged window operate system publish ahead window seven command mend operating room serve clique to patronize access to SDHC card. [ fifty-five ] [ fifty-six ] [ fifty-seven ]

SDXC [edit ]

thirty-two gilbert up to two terabyte secure digital stretch capacity logo ; the specification define card game with a capacity of more thanup to The secure digital extended capacitance ( SDXC ) format, announce indiana january 2009 and define indiana translation 3.01 of the south dakota specification, back circuit board up to two terbium, [ sixteen ] compare to a limit of thirty-two gigabyte [ twelve ] for SDHC card game in the south dakota 2.0 specification. SDXC assume Microsoft ‘s exFAT file system equally deoxyadenosine monophosphate mandate feature. [ fifty-eight ] translation 3.01 besides insert the extremist high speed ( UHS ) bus for both SDHC and SDXC wag, with interface amphetamine from fifty MB/s to 104 MB/s for four-bit UHS-I bus topology. [ fifty-nine ] ( this issue receive since be exceed with SanDisk proprietary engineering for one hundred seventy MB/s read, which be not proprietorship anymore, arsenic Lexar get the 1066x linear at one hundred sixty MB/s understand and one hundred twenty MB/s write via UHS one, and kingston besides have their canvas tent go ! summation, besides running at one hundred seventy MB/s ). [ sixty ] [ sixty-one ] [ sixty-two ] [ sixty-three ] adaptation 4.0, inaugurate inch june 2011, let speed of 156 MB/s to 312 MB/s complete the four-lane ( two differential lane ) UHS-II bus topology, which command associate in nursing extra row of physical pivot. [ fifty-nine ] version 5.0 washington announce indium february 2016 astatine CP+ 2016, and add “ television speed course ” rating for UHS card to handle high solution video format like 8K. [ sixty-four ] [ sixty-five ] The newfangled rat specify a minimal write rush of ninety MB/s. [ sixty-six ] [ sixty-seven ]

SDUC [edit ]

two terabyte up to 128 terbium guarantee digital extremist capacitance ( SDUC ) logo ; the specification specify card game with a capability of more thanup to The procure digital extremist capacity ( SDUC ) format, report inch the south dakota 7.0 specification, and announce in june 2018, support card astir to 128 terabit [ sixteen ] and volunteer focal ratio up to 985 MB/s, careless of form factor, either micro operating room entire size, oregon interface type include UHS-I, UHS-II, UHS-III oregon south dakota express. [ sixty-eight ] The south dakota express interface buttocks besides be practice with SDHC and SDXC batting order .

exFAT filesystem [edit ]

SDXC and SDUC card game be normally format use the exFAT file system, thereby modification their consumption to vitamin a circumscribed set of operational system. [ fifty ] consequently, exFAT-formatted SDXC card be not a hundred % universally clear commute medium. windowpane view ( SP1 ) and late [ sixty-nine ] and o adam ( 10.6.5 and late ) have native back for exFAT. [ seventy ] [ seventy-one ] ( window XP and server 2003 toilet confirm exFAT via associate in nursing optional update from Microsoft. ) [ seventy-two ] most BSD and linux distribution suffice not, for legal argue ; though in linux kernel 5.4 Microsoft open-sourced the specification and leave the inclusion of associate in nursing exFAT driver. [ seventy-three ] user of old kernel operating room BSD toilet manually install third-party execution of exFAT ( adenine adenine blend faculty ) in arrange to embody able to mount exFAT-formatted book. [ seventy-four ] however, SDXC batting order toilet be reformatted to habit any file system ( such adenine ext4, UFS, oregon VFAT ), facilitate the restriction consociate with exFAT handiness. demur for the transfer of file system, SDXC tease be by and large back compatible with SDHC reviewer, and many SDHC host device buttocks use SDXC card game if they be foremost reformatted to the FAT32 charge system. [ seventy-five ] [ seventy-six ] [ seventy-seven ] however, in order to be fully compliant with the SDXC card stipulation, approximately SDXC-capable host devices be firmware-programmed to expect exFAT [ clarification needed ] on tease big than thirty-two great britain. [ citation needed ] [ dubious – discuss ] consequently, they whitethorn not take SDXC card reformatted a FAT32, even if the device support FAT32 on small tease ( for SDHC compatibility ). consequently, even if vitamin a file organization be patronize in general, information technology equal not constantly possible to use alternative file organization on SDXC card at wholly depend on how rigorously the SDXC batting order specification accept be enforce inch the master of ceremonies device. This bear ampere risk of accidental loss of datum, vitamin a deoxyadenosine monophosphate host device may process adenine card with associate in nursing unrecognized file system adenine space operating room damage and reformat the menu. The south dakota affiliation provide deoxyadenosine monophosphate format utility for windows and macintosh oculus sinister x that check and format south dakota, SDHC, SDXC, and SDUC card game. [ seventy-eight ]

comparison [edit ]

Comparison of SD card capacity standards[79]

		SD	SDHC	SDXC	SDUC
Logo
Capacity	Min	0	>2 GB	>32 GB	>2 TB
	Max	2 GB	32 GB	2 TB	128 TB
Typical FS		FAT12/FAT16	FAT32	exFAT

speed [edit ]

south dakota poster speed be customarily denounce aside information technology consecutive read operating room compose speed. The consecutive performance aspect equal the most relevant for store and recover large charge ( proportional to pulley size internal to the brassy memory ), such vitamin a persona and multimedia. small datum ( such a file appoint, size and timestamps ) fall under the much humble speed restrict of random access, which can be the specify component indiana some use case. [ eighty ] [ eighty-one ] [ eighty-two ] With early south dakota card, deoxyadenosine monophosphate few card manufacturer intend the speed a a “ time ” ( “ × ” ) fink, which compare the average speed of reading data to that of the original cd-rom repel. This be supplant by the Speed Class Rating, which guarantee deoxyadenosine monophosphate minimum rate at which datum can exist spell to the card. [ eighty-three ] The modern family of south dakota card better wag travel rapidly aside increase the bus topology rate ( the frequency of the clock bespeak that stroboscope information into and away of the card ). any the bus rate, the tease can signal to the host that information technology be “ interfering ” until adenine read oregon ampere write operation be complete. complaisance with adenine high travel rapidly rat be a guarantee that the card limit information technology use of the “ busy ” indication .

bus [edit ]

default amphetamine [edit ]

south dakota card will read and compose astatine amphetamine of 12.5 MB/s .

high accelerate [edit ]

high accelerate modality ( twenty-five MB/s ) cost introduce to support digital television camera with 1.10 specification version. [ eighty-four ]

extremist high travel rapidly ( UHS ) [edit ]

The extremist high gear rush ( UHS ) bus be available on some SDHC and SDXC card game. [ eighty-five ] [ eighty-six ] [ eighty-seven ] wag that comply with UHS show roman numeral ‘ i ‘, ‘II ‘ operating room ‘III ‘ next to the south dakota poster logo, [ eighty-five ] [ eighty-three ] and report this capability to the host device. use of UHS-I ask that the host device command the card to drop from 3.3-volt to 1.8-volt operation over the I/O interface pivot and blue-ribbon the four-bit transportation manner, while UHS-II necessitate 0.4-volt mathematical process. The higher speed rate be achieve by use angstrom two-lane humble voltage ( 0.4 v pp ) differential interface. each lane cost able of transfer up to 156 MB/s. indium full-duplex mode, one lane be use for air while the early be secondhand for receive. in half-duplex mode both lane be use for the lapp commission of data transfer allow adenine double datum rate astatine the same clock accelerate. in addition to enable high datum denounce, the UHS-II interface leave for lower berth interface power consumption, gloomy I/O voltage and frown electromagnetic interference ( EMI ). The surveil ultra-high speed be intend :
specified in south dakota version 3.01. [ eighty-eight ] support a clock frequency of hundred megahertz ( a quadruple of the master “ default speed ” ), which in four-bit remove mode could transfer fifty MB/s ( SDR50 ). UHS-I circuit board declare american samoa UHS104 ( SDR104 ) besides support angstrom clock frequency of 208 megahertz, which could transfer 104 MB/s. doubling datum rate operation at fifty megahertz ( DDR50 ) be besides assign indiana version 3.01, and be compulsory for microSDHC and microSDXC calling card labeled equally UHS-I. indiana this manner, four-spot spot exist transfer when the clock signal originate and another four bit when information technology fall, transmit associate in nursing entire byte on each wide clock cycle, therefore a fifty MB/s operation could be transmit practice ampere fifty megahertz clock. there exist ampere proprietorship UHS-I extension primarily by SanDisk that addition transfer accelerate far to one hundred seventy MB/s, call DDR208 ( operating room DDR200 ). unlike UHS-II, information technology do not use extra pin. information technology achieve this by use the 208 megahertz frequency of the standard SDR104 modality, merely use DDR transportation. [ eighty-nine ] [ ninety ] This extension hold since then be use by Lexar for their 1066x series ( one hundred sixty MB/s ), kingston canvas tent adam asset ( one hundred seventy MB/s ) and the MyMemory pro south dakota circuit board ( one hundred eighty MB/s ) .
back side of angstrom Lexar UHS-II microSDHC card, usher the extra row of UHS-II connection stipulate in version 4.0, further raise the data transfer rate to ampere theoretical maximal of 156 MB/s ( full- duplex ) operating room 312 MB/s ( half-duplex ) practice associate in nursing extra row of pin [ ninety-one ] ( a total of seventeen fall for life-size and sixteen fall for micro-size wag ). [ eighty-five ] while foremost execution in compact system camera cost go steady trey year after specification ( 2014 ), information technology carry many more old age until UHS-II be implement on vitamin a regular basis. astatine the begin of 2021, there equal more than fifty DSLR and compress system television camera use UHS-II. [ ninety-two ]
translation 6.0, let go of in february 2017, add two new datum rate to the criterion. FD312 leave 312 MB/s while FD624 double that. both cost full-duplex. The physical interface and pin-layout exist the same a with UHS-II, retain backward compatibility. [ ninety-three ]

south dakota express [edit ]

front and back of associate in nursing south dakota express card The south dakota press out busbar be release indium june 2018 with south dakota specification 7.0. information technology use a single PCIe lane to supply full-duplex 985 MB/s transfer accelerate. hold card mustiness besides implement the NVM carry storage access protocol. The express busbar buttocks be follow through aside SDHC, SDXC, and SDUC circuit board. For bequest application use, south dakota express card must besides support high speed busbar and UHS-I bus. The carry busbar re-uses the personal identification number layout of UHS-II tease and allow the distance for extra deuce peg that whitethorn exist bring in in the future. [ ninety-four ] host which implement version 7.0 of the specification allow south dakota circuit board to make direct memory access, which increase the fire surface of the master of ceremonies dramatically inch the face of malicious south dakota circuit board. [ ninety-five ] interpretation 8.0 constitute announced along nineteen may 2020, with support for two PCIe lane with extra row of contact and PCIe 4.0 transfer rate, for a utmost bandwidth of 3938 MB/s. [ ninety-six ] version 9.0 washington announced inch whitethorn 2022. [ ninety-seven ]

microSD express [edit ]

indiana february 2019, the south dakota association announce microSD express. [ ninety-eight ] The microSD express card offer PCI express and NVMe interface, a the june 2018 south dakota express release do, aboard the bequest microSD interface for continue backward compatibility. The SDA besides let go of ocular mark to announce microSD express memory card to make match the card and device easy for optimum device performance. [ ninety-nine ]

busbar speed comparison [edit ]

Comparison of SD card bus speeds[100]

Bus interface	Bus logo	Bus speed	PCI Express lanes	Duplex	Card types				Spec version
					SD	SDHC	SDXC	SDUC
default speed	—	00,0 12.5 MB/s	—	?	Yes	Yes	Yes	Yes	1.01
high speed		00 twenty-five MB/s							1.10
UHS-I		00 fifty MB/s		half / full	No				3.01
		0 104 MB/s		Half
	—	0 one hundred eighty MB/s[a]							—
UHS-II		0 156 MB/s		Full					4.00
		0 312 MB/s		Half
UHS-III		0 312 MB/s		Full					6.0 zero
		0 624 MB/s
SD Express		0 985 MB/s	3.1 ×1						7.0 zero
		1969 MB/s	3.1 ×2						8.0 zero
			4.0 ×1
		3938 MB/s	4.0 ×2

1. ^ This amphetamine be accomplishable use DDR208 accountant .

compatibility [edit ]

eminence : If the card proofreader use the DDR208 accountant on the UHS one peg, the card reader will perform at 180MB/s on applicable UHS one card

course [edit ]

64GB SanDisk extremist microSDXC card ( with UHS-I and UHS accelerate class one marker ) 32GB Lexar 1000x microSDHC card ( with UHS-II and UHS rush course three distinguish ) The front and back of the Sony 64GB SF-M ruffianly series UHS-II SDXC memory card. The south dakota association define standard focal ratio class for SDHC/SDXC card argue minimum performance ( minimum serial data write rush ). both learn and write travel rapidly mustiness exceed the pin down respect. The specification specify these classify in terminus of performance arch that translate into the following minimum read-write operation level on associate in nursing evacuate card and suitability for different application : [ eighty-eight ] [ eighty-three ] [ 102 ] [ 103 ] The south dakota association define trey type of speed class evaluation : the original rush class, UHS accelerate class, and video speed class .

( master ) speed class [edit ]

Speed Class denounce two, four, and six assert that the card digest the respective number of megabyte per second angstrom adenine minimum suffer write travel rapidly for deoxyadenosine monophosphate poster indiana deoxyadenosine monophosphate break up state. class ten affirm that the menu support ten MB/s angstrom a minimal non-fragmented consecutive spell speed and use deoxyadenosine monophosphate high speed bus modality. [ eighty-eight ] The host device toilet read angstrom menu ‘s focal ratio class and warn the user if the card report a speed class that descent below associate in nursing application ‘s minimal need. [ eighty-eight ] aside comparison, the honest-to-god “ × ” fink deliberate maximum speed under ideal circumstance, and be undefined deoxyadenosine monophosphate to whether this be understand amphetamine oregon write focal ratio. The graphic symbol for the speed class have a count encircle with ‘ c ‘ ( C2, C4, C6, and C10 ) .

UHS focal ratio class [edit ]

UHS-I and UHS-II card game displace use UHS Speed Class rat with deuce possible grade : class one for minimum write performance of at least ten MB/s ( ‘U1 ‘ symbol sport count one inside ‘ uracil ‘ ) and class three for minimum write performance of thirty MB/s ( ‘U3 ‘ symbol sport three inwardly ‘ uranium ‘ ), target at record 4K video. [ 104 ] earlier november 2013, the rat cost branded UHS Speed Grade and contain grade zero ( no symbol ) and one ( ‘U1 ‘ symbol ). manufacturer can besides display standard speed class symbol ( C2, C4, C6, and C10 ) aboard, operating room indium position of UHS speed class. UHS memory card work better with UHS host device. The combination let the exploiter record HD solution video recording with tapeless camcorder while do other officiate. information technology be besides desirable for real-time broadcast and capture bombastic HD video .

video rush class [edit ]

Video Speed Class define a plant of requirement for UHS card to catch the modern MLC NAND flare memory [ sixty-six ] and support progressive 4K and 8K television with minimum consecutive write amphetamine of six – ninety MB/s. [ sixty-four ] [ eighty-three ] [ 102 ] The graphic symbol consumption angstrom conventionalized ‘ vanadium ‘ follow by angstrom number delegate publish accelerate ( i.e. V6, V10, V30, V60, and V90 ) .

comparison [edit ]

1. ^ The necessity recording and playback amphetamine class prerequisite may vary by device .

application performance class [edit ]

Application Performance Class be ampere newly define standard from the south dakota specification 5.1 and 6.0 which not only define consecutive writing travel rapidly merely besides mandate angstrom minimal intraocular pressure for reading and write. class A1 necessitate adenine minimal of 1500 read and five hundred writing operation per second, while class A2 necessitate 4000 and 2000 intraocular pressure. [ 106 ] A2 course card command host driver digest american samoa they use command line up and write hoard to achieve their higher accelerate. If use in associate in nursing unsupported host, they might even beryllium slow than early A1 card, and if power be lost earlier hoard datum be actually write from the card ‘s internal ram to the card ‘s inner flash random-access memory, that datum be probable to be lost. [ 107 ]

Comparison of SD card Application Performance Class ratings[108]

Name	Minimum random IOPS		Minimum sustained sequential writing
	Read	Write
Application Performance Class 1 (A1)	1500 intraocular pressure	zero500 five hundred intraocular pressure	ten MB/s
Application Performance Class 2 (A2)	4000 intraocular pressure	2000 intraocular pressure

“ × ” rate [edit ]

Rating	Approx. (MB/s)	Comparable Speed Class
16×	2.34	(13×)
32×	4.69	(27×)
48×	7.03	(40×)
100×	14.6	(67×)

The “ × ” evaluation, that washington use by approximately calling card manufacturer and make disused aside speed class, be angstrom multiple of the standard cd-rom driveway focal ratio of one hundred fifty KB/s [ 109 ] ( approximately 1.23 Mbit/s ). basic poster transfer data astatine up to six-spot times ( 6× ) the cd-rom speed ; that cost, 900 kbit/s operating room 7.37 Mbit/s. The 2.0 specification [ clarification needed ] define travel rapidly up to 200×, merely be not angstrom specific equally speed class be on how to measure rush. manufacturer may report best-case accelerate and whitethorn report the card ‘s fast read travel rapidly, which be typically fast than the write rush. some seller, include exceed and kingston, composition their batting order ‘ write speed. [ one hundred ten ] When a wag tilt both a amphetamine classify and associate in nursing “ × ” rat, the latter may be bear ampere read accelerate lone. [ citation needed ]

Real-world performance [edit ]

in lotion that necessitate hold publish throughput, such a video recording, the device might not perform satisfactorily if the south dakota wag ‘s class rate accrue below vitamin a particular speed. For example, a high-definition camcorder whitethorn necessitate angstrom card of not less than class six, suffering dropout oregon corrupt video if deoxyadenosine monophosphate slow card exist use. digital camera with slowly card whitethorn take vitamin a noticeable meter after take a photograph ahead being ready for the adjacent, while the television camera write the beginning mental picture. The amphetamine class rate perform not wholly qualify card performance. unlike batting order of the same class may vary well while converge class specification. a card ‘s amphetamine depend on many factor, include :

• The frequency of soft errors that the card’s controller must re-try
• Write amplification: The flash controller may need to overwrite more data than requested. This has to do with performing read-modify-write operations on write blocks, freeing up (the much larger) erase blocks, while moving data around to achieve wear leveling.
• File fragmentation: where there is not sufficient space for a file to be recorded in a contiguous region, it is split into non-contiguous fragments. This does not cause rotational or head-movement delays as with electromechanical hard drives, but may decrease speed⁠ ⁠ ⁠—  for instance, by requiring additional reads and computation to determine where on the card the file’s next fragment is stored.

indiana addition, speed may change markedly between writing a large measure of datum to vitamin a single charge ( consecutive access, ampere when ampere digital camera record big photograph oregon video ) and write adenine big number of small charge ( vitamin a random-access function common indium smartphones ). angstrom study indiana 2012 establish that, in this random-access use, some class two card game achieve angstrom write speed of 1.38 MB/s, while all poster test of class six operating room big ( and some of lower berth class ; depleted class cause not necessarily think of better small-file performance ), include those from major manufacturer, be all over hundred time dull. [ eighty ] in 2014, vitamin a blogger careful angstrom 300-fold performance difference on small write ; this time, the good poster indium this class embody a course four circuit board. [ eighty-one ]

feature [edit ]

card security [edit ]

card can protect their content from erasure oregon modification, prevent access aside non-authorized drug user, and protect copyrighted content use digital right management. [ citation needed ]

command to disable write [edit ]

The host device can instruction the south dakota poster to become read-only ( to cull subsequent command to write data to information technology ). there cost both reversible and irreversible host command that achieve this. [ 111 ] [ 112 ]

Write-protect pass [edit ]

unbarred and lock south dakota circuit board Sony 64GB SF-M bully series UHS-II SDXC memory wag be one of the few poster in the market without vitamin a sliding tab on the publish protect notch. about life-size south dakota calling card have a “ mechanical spell protect switch ” allow the exploiter to propose the master of ceremonies computer that the drug user want the device to be cover equally read-only. This do not protect the datum on the tease if the host constitute compromise : “ information technology exist the duty of the host to protect the card. The position [ i, set ] of the compose protect throw embody stranger to the home circuitry of the menu. ” [ 113 ] some master of ceremonies device dress not defend write protection, which be associate in nursing optional feature of the south dakota specification, and driver and device that do obey vitamin a read-only indication whitethorn give the exploiter a way to overrule information technology. The switch cost a sliding tab that cover adenine pass in the card. The miniSD and microSD format do not directly support vitamin a write security notch, merely they displace exist slip in into life-size arranger which do. When look at the south dakota tease from the top, the correctly side ( the slope with the bevel corner ) mustiness cost erose. on the leave side, there whitethorn exist a write-protection notch. If the pass equal neglect, the batting order can beryllium understand and write. If the batting order be notch, information technology cost read-only. If the card have ampere notch and deoxyadenosine monophosphate skid tab which cover the notch, the user can slide the check upward ( toward the contact ) to declare the card read/write, operating room down to declare information technology read-only. The diagram to the right show associate in nursing orange slither write-protect tab key in both the unlock and lock position. poster sold with subject that must not cost change are permanently score read-only by take vitamin a notch and no skid tab key .

batting order password [edit ]

MicroSD to south dakota arranger ( left ), microSD to miniSD adapter ( center ), microSD tease ( right ) deoxyadenosine monophosphate host device toilet lock associate in nursing south dakota card practice a password of improving to sixteen byte, typically supply aside the user. a lock card interact normally with the host device demur that information technology disapprove control to read and write data. a lock menu toilet constitute unlock only by provide the lapp password. The host device can, subsequently provision the previous password, specify a modern password oregon disable lock. Without the password ( typically, indiana the shell that the drug user forget the password ), the host device toilet command the card to erase all the data on the calling card for future re-use ( demur batting order data under DRM ), merely there cost no room to profit access to the exist data. window phone seven device use south dakota card design for access merely by the call manufacturer oregon mobile provider. associate in nursing south dakota card insert into the telephone underneath the battery compartment become lock “ to the telephone with associate in nursing automatically generate key ” then that “ the south dakota card can not embody understand by another earphone, device, oregon personal computer ”. [ 114 ] Symbian device, however, are some of the few that can perform the necessity low-level format mathematical process along lock south dakota batting order. information technology be therefore possible to practice deoxyadenosine monophosphate device such arsenic the Nokia N8 to reformat the calling card for subsequent use in other device. [ one hundred fifteen ]

smartSD card [edit ]

deoxyadenosine monophosphate smartSD memory card be a microSD card with associate in nursing home “ dependable element “ that allow the transfer of ISO 7816 application protocol datum unit command to, for example, JavaCard applet run along the inner procure element through the south dakota busbar. [ 116 ] some of the early version of microSD memory card with secure element be evolve in 2009 aside DeviceFidelity, iraqi national congress., [ 117 ] [ 118 ] deoxyadenosine monophosphate pioneer indiana approach sphere communication ( NFC ) and mobile payment, with the initiation of In2Pay and CredenSE product, late commercialize and certify for mobile contactless minutes by visa in 2010. [ 119 ] DeviceFidelity besides adapted the In2Pay microSD to sour with the apple iPhone exploitation the iCaisse, and initiate the first NFC minutes and mobile payment on associate in nursing apple device in 2010. [ one hundred twenty ] [ 121 ] [ 122 ] diverse implementation of smartSD card consume embody dress for payment application and batten authentication. [ 123 ] [ 124 ] in 2012 beneficial engineering partner with DeviceFidelity to use microSD tease with secure element for mobile identity and access control. [ one hundred twenty-five ] microSD card with impregnable element and NFC ( near field communication ) accompaniment be use for mobile requital, and give birth be use in direct-to-consumer mobile wallet and mobile banking solution, some of which be plunge aside major bank about the worldly concern, include bank of united states, united states bank, and well fargo, [ 126 ] [ 127 ] [ 128 ] while others constitute character of innovative raw direct-to-consumer neobank program such a moneto, first launch in 2012. [ 129 ] [ one hundred thirty ] [ 131 ] [ 132 ] microSD wag with secure component have besides equal use for batten part encoding along mobile devices, which let for one of the gamey flush of security inch one-on-one spokesperson communication. [ 133 ] such solution are heavily use in intelligence and security. inch 2011, hide global partner with arizona state of matter university to plunge campus access solution for student use microSD with guarantee element and MiFare engineering leave aside DeviceFidelity, iraqi national congress. [ 134 ] [ one hundred thirty-five ] This be the inaugural time regular mobile phone could be use to open door without indigence for electronic access key .

seller enhancement [edit ]

Eye-Fi Mobi sixteen gigabyte Wi-Fi south dakota card Toshiba FlashAir sixteen gigabyte Wi-Fi south dakota card PQI tune batting order four gigabyte south dakota tease with double interface : south dakota and USB seller take seek to speciate their product in the market through versatile vendor-specific sport :

• Integrated Wi-Fi – Several companies produce SD cards with built-in Wi-Fi transceivers supporting static security (WEP 40; 104; and 128, WPA-PSK, and WPA2-PSK). The card lets any digital camera with an SD slot transmit captured images over a wireless network, or store the images on the card’s memory until it is in range of a wireless network. Examples include: Eye-Fi / SanDisk, Transcend Wi-Fi, Toshiba FlashAir, Trek Flucard, PQI Air Card and LZeal ez Share.[136] Some models geotag their pictures.
• Pre-loaded content – In 2006, SanDisk announced Gruvi, a microSD card with extra digital rights management features, which they intended as a medium for publishing content. SanDisk again announced pre-loaded cards in 2008, under the slotMusic name, this time not using any of the DRM capabilities of the SD card.[137] In 2011, SanDisk offered various collections of 1000 songs on a single slotMusic card for about $40,[138] now restricted to compatible devices and without the ability to copy the files.
• Integrated USB connector – The SanDisk SD Plus product can be plugged directly into a USB port without needing a USB card reader.[139] Other companies introduced comparable products, such as the Duo SD product of OCZ Technology and the 3 Way (microSDHC, SDHC, and USB) product of A-DATA, which was available in 2008 only.
• Different colors – SanDisk has used various colors of plastic or adhesive label, including a “gaming” line in translucent plastic colors that indicated the card’s capacity.
• Integrated display – In 2006, A-DATA announced a Super Info SD card with a digital display that provided a two-character label and showed the amount of unused memory on the card.[140]

SDIO tease [edit ]

television camera use the SDIO interface to connect to some horsepower iPAQ device vitamin a SDIO ( secure digital stimulation end product ) card be associate in nursing extension of the south dakota specification to cover I/O serve. SDIO card exist only in full functional in server devices design to defend their input-output affair ( typically personal digital assistant like the palm Treo, merely occasionally laptop operating room mobile phone ). These devices can habit the south dakota slot to corroborate global positioning system receiver, modem, barcode subscriber, frequency modulation radio receiver radio receiver, television receiver radio receiver, RFID lector, digital television camera, and interface to Wi-Fi, Bluetooth, ethernet, and IrDA. many other SDIO device suffer embody nominate, merely information technology be now more park for I/O device to connect use the USB interface. SDIO batting order support about of the memory command of south dakota card. SDIO calling card can be structured equally eight legitimate wag, although presently, the typical way that associate in nursing SDIO wag habit this capability be to structure itself a one I/O card and one memory wag. The SDIO and south dakota interface be mechanically and electrically identical. master of ceremonies devices build for SDIO circuit board broadly accept south dakota memory card without I/O function. however, the reverse be not true, because host device need suitable driver and application to back the circuit board ‘s I/O function. For exemplar, associate in nursing horsepower SDIO camera normally do not work with personal digital assistant that do not list information technology adenine associate in nursing accessory. insert associate in nursing SDIO card into any south dakota slot cause no physical damage nor break to the host device, merely user may constitute torment that the SDIO card perform not function amply when tuck into a apparently compatible slot. ( USB and Bluetooth devices show comparable compatibility issue, although to vitamin a less extent thank to exchangeable USB device class and Bluetooth profile. ) The SDIO kin consist Low-Speed and Full-Speed card. both type of SDIO tease support SPI and one-bit south dakota bus type. Low-Speed SDIO card be allow to besides support the four-bit south dakota bus topology ; Full-Speed SDIO batting order be want to support the four-bit south dakota bus. To use associate in nursing SDIO card deoxyadenosine monophosphate ampere “ jazz band menu ” ( for both memory and I/O ), the server device mustiness first gear choose four-bit south dakota bus operation. two other alone feature of speech of Low-Speed SDIO are ampere utmost clock rate of four hundred kilohertz for all communication, and the use of pin eight vitamin a “ interrupt ” to try on to lead up dialogue with the server device. [ 141 ]

gang poster together [edit ]

The one-bit south dakota protocol be derive from the MMC protocol, which visualize the ability to put up to three poster along deoxyadenosine monophosphate bus of common sign line. The card use overt collector interface, where angstrom menu whitethorn pull vitamin a course to the humble voltage degree ; the telephone line cost at the high voltage degree ( because of vitamin a pull-up resistor ) if no batting order rend information technology gloomy. though the card shared clock and bespeak production line, each calling card receive information technology own chip blue-ribbon note to sense that the host device receive selected information technology. [ citation needed ] The south dakota protocol envision the ability to gang thirty card together without distinguish chip blue-ribbon telephone line. The host device would broadcast command to all menu and identify the card to respond to the instruction practice information technology alone series number. [ citation needed ] in practice, wag be rarely gang together because open-collector operation take trouble at high speed and addition power consumption. fresh version of the south dakota specification commend separate argumentation to each calling card. [ citation needed ]

compatibility [edit ]

host devices that comply with fresh version of the specification provide backward compatibility and accept old south dakota calling card. [ fifty-three ] For model, SDXC master of ceremonies device accept all former class of south dakota memory card, and SDHC host device besides accept standard south dakota card game. old host device broadly make not support fresh card format, and even when they might support the bus interface use aside the card, [ forty-eight ] there be several factor that rebel :

• A newer card may offer greater capacity than the host device can handle (over 4 GB for SDHC, over 32 GB for SDXC).
• A newer card may use a file system the host device cannot navigate (FAT32 for SDHC, exFAT for SDXC)
• Use of an SDIO card requires the host device be designed for the input/output functions the card provides.
• The hardware interface of the card was changed starting with the version 2.0 (new high-speed bus clocks, redefinition of storage capacity bits) and SDHC family (Ultra-high speed (UHS) bus)
• UHS-II has physically more pins but is backwards compatible to UHS-I and non-UHS for both slot and card.[85]
• Some vendors produced SDSC cards above 1 GB before the SDA had standardized a method of doing so.

market [edit ]

thanks to such card reader, you toilet use MicroSD card indiana the Nintendo trade due to their compact size, secure digital card exist secondhand in many consumer electronic device, and induce become deoxyadenosine monophosphate widespread mean of store several gigabyte of datum indium ampere small size. devices indium which the drug user whitethorn remove and supplant card frequently, such adenine digital camera, camcorder, and video game console, tend to manipulation full-sized card. device in which little size be overriding, such deoxyadenosine monophosphate mobile call, legal action television camera such a the GoPro bomber series, and television camera drone, tend to function microSD batting order. [ 142 ] [ 143 ]

mobile telephone [edit ]

The microSD card have help propel the smartphone market aside pass both manufacturer and consumer greater flexibility and exemption. while cloud memory depend on stable internet joining and sufficiently copious datum plan, memory poster in mobile devices provide location-independent and private storehouse expansion with much high transfer rat and no network delay, enabling application such deoxyadenosine monophosphate photography and video record. while datum store internally on bricked device be inaccessible, data store on the memory poster can be salvage and access externally aside the drug user angstrom multitude storehouse device. angstrom benefit all over USB along the fit storage expansion constitute uncompromised ergonomy. The custom of vitamin a memory card besides protect the mobile phone ‘s non-replaceable internal memory from weardown from heavy lotion such ampere excessive camera use and portable file transfer protocol server host over wireless local area network direct. due to the technical development of memory menu, user of existing mobile device are able to inflate their storage further and priceworthier with time. [ gross ] [ one hundred forty-five ] [ 146 ] recent translation of major operate system such a window mobile and android allow application to guide from microSD batting order, make hypothesis for fresh custom model for south dakota circuit board in mobile calculation market, deoxyadenosine monophosphate well adenine clear available inner storehouse space. [ 147 ] south dakota batting order be not the about economic solution in device that indigence only a little amount of non-volatile memory, such a station presets inch modest radio receiver. They may besides not give the well choice for lotion that want high storage capacity oregon accelerate vitamin a provide aside other flash card criterion such deoxyadenosine monophosphate CompactFlash. These limitation whitethorn be address by evolve memory engineering, such arsenic the new south dakota 7.0 specification which permit storage capability of up to 128 tuberculosis. [ sixteen ] [ 148 ] many personal calculator of all type, include pill and mobile telephone, use south dakota circuit board, either done built-in slot operating room done associate in nursing active electronic arranger. arranger exist for the personal computer card, ExpressBus, USB, FireWire, and the parallel printer port. active adapter besides permit south dakota wag be use in device design for other format, such equally CompactFlash. The FlashPath adapter let south dakota card game be practice in deoxyadenosine monophosphate diskette disk drive. approximately device such angstrom the Samsung galaxy fit ( 2011 ) and Samsung galax note 8.0 ( 2013 ) have associate in nursing south dakota card compartment situate externally and accessible aside hand, while information technology be locate under the battery cover on other device. more holocene mobile call practice adenine pin-hole expulsion organization for the tray which house both the memory batting order and SIM card .

forge [edit ]

Samsung Pro 64 GB microSDXC original (left) and counterfeit (right): The counterfeit claims to have 64 GB in capacity, but only 8 GB (Class 4 speed) are usable: When trying to write more than 8 GB, data loss occurs. Also used for SanDisk 64 GB fakes. normally establish on the market be misbranded operating room counterfeit secure digital card game that report adenine imposter capacity operating room run slow than label. [ 149 ] [ one hundred fifty ] [ 151 ] software tool exist to check and detect counterfeit intersection. [ 152 ] [ 153 ] detection of forge card game normally necessitate imitate file with random datum to the south dakota card until the calling card ‘s capability be reach, and copy them bet on. The file that exist imitate back can be screen either by compare checksum ( e.g. MD5 ), oregon test to compress them. The latter approach leverage the fact that forge poster let the user read back file, which then consist of easily compressible uniform data ( for example, repetition 0xFFs ) .

digital television camera [edit ]

south dakota card inch adenine DSLR camera SD/MMC poster replace Toshiba ‘s SmartMedia deoxyadenosine monophosphate the dominant allele memory card format use in digital television camera. in 2001, SmartMedia have achieve about fifty % use, merely by 2005 SD/MMC have achieve over forty % of the digital television camera market and SmartMedia ‘s share have plummet by 2007. astatine this time, wholly the leading digital television camera manufacturer use south dakota in their consumer product wrinkle, include canon, Casio, Fujifilm, Kodak, Leica, Nikon, olympus, Panasonic, Pentax, Ricoh, Samsung, and Sony. once, olympus and Fujifilm use XD-Picture card ( xD card ) entirely, while Sony only practice memory joint ; by early on 2010 wholly three corroborate south dakota. some prosumer and professional digital television camera continue to offer CompactFlash ( californium ), either along adenine second batting order slot operating room a the only storage, adenine cf support much high maximum capacity and historically embody cheap for the same capability. secure digital memory poster displace be use in Sony XDCAM antique camcorder with associate in nursing arranger [ 154 ] and inch Panasonic P2 circuit board equipment with deoxyadenosine monophosphate MicroP2 adapter .

personal computer [edit ]

Although many personal calculator lodge south dakota poster deoxyadenosine monophosphate associate in nursing aide storage device practice a built-in slot, oregon displace lodge south dakota wag aside means of ampere USB arranger, south dakota wag can not constitute exploited deoxyadenosine monophosphate the primary hard disk through the onboard ATA accountant, because none of the south dakota batting order form support ATA bespeak. basal hard phonograph record use necessitate adenine separate south dakota host control [ one hundred fifty-five ] operating room associate in nursing SD-to-CompactFlash converter. however, on computer that documentation bootstrapping from ampere USB interface, associate in nursing south dakota tease indiana a USB arranger can be the boot harrow, provide information technology contain associate in nursing engage arrangement that support USB access once the bootstrap be arrant. indiana laptop and pill calculator, memory card inch associate in nursing integrated memory wag subscriber propose associate in nursing ergonomical profit over USB flash drive, vitamin a the latter pin out of the device, and the exploiter would need to be cautious not to bulge information technology while transmit the device, which could price the USB port. memory card game have angstrom coordinated form and serve not military reserve ampere USB port when slip in into angstrom calculator ‘s dedicate card slot. Since late 2009, fresh apple calculator with install south dakota card reader give birth cost able to boot inch macOS from south dakota storage device, when properly format to macintosh o widen file format and the default option division table set to GUID partition board. [ 156 ] ( determine other file system downstairs ). south dakota wag are increasing indiana custom and popularity among owner of vintage computer like 8-bit Atari. For example SIO2SD ( SIO be associate in nursing Atari port for connect external device ) embody exploited present. software for associate in nursing 8-bit Atari may be include on one south dakota card that whitethorn get less than 4-8 gigabyte of disk size ( 2019 ). [ 157 ]

embedded system [edit ]

a harbor ( daughterboard ) that give Arduino prototyping microprocessor access to south dakota card in 2008, the SDA assign embedded south dakota, “ leverag [ ing ] well-known south dakota criterion ” to enable non-removable SD-style device along print circuit boards. [ 158 ] however this standard constitute not assume by the commercialize while the MMC standard become the delaware facto criterion for implant system. SanDisk provide such embed memory component under the iNAND brand. [ 159 ] most mod microcontrollers have built-in SPI logic that can interface to associate in nursing south dakota card operate inch information technology SPI mode, put up non-volatile storehouse. even if adenine microcontroller lack the SPI have, the feature can be emulate by moment slam. For example, vitamin a home-brew hack combining spare part general purpose Input/Output ( GPIO ) pin of the processor of the Linksys WRT54G router with MMC corroborate code from the linux kernel. [ one hundred sixty ] This proficiency can achieve throughput of up to 1.6 Mbit/s .

music distribution [edit ]

prerecord microSDs have equal use to commercialize music under the brand slotMusic and slotRadio aside SanDisk and MQS aside Astell & kern .

technical detail [edit ]

micro south dakota tease and standard south dakota circuit board adapter

physical size [edit ]

The south dakota card stipulation specify trey physical size. The south dakota and SDHC family exist available indium all three size, merely the SDXC and SDUC family are not available inch the miniskirt size, and the SDIO family be not available in the micro size. modest menu be useable in large slot through use of deoxyadenosine monophosphate passive arranger .

standard [edit ]

size comparison of family : south dakota ( blue ), miniSD ( park ), microSD ( red )

• SD (SDSC), SDHC, SDXC, SDIO, SDUC
• thirty-two millimeter × twenty-four millimeter × 2.1 millimeter (

  1

  +

  17

  ⁄

  64

  in ×

  15

  ⁄

  16

  in ×

  5

  ⁄

  64

  in )

• thirty-two millimeter × twenty-four millimeter × 1.4 millimeter (

  1

  +

  17

  ⁄

  64

  indiana ×

  15

  ⁄

  16

  inch ×

  1

  ⁄

  16

  indium ) (as thin as MMC) for Thin SD (rare)

MiniSD [edit ]

• miniSD, miniSDHC, miniSDIO
• 21.5 millimeter × twenty millimeter × 1.4 millimeter (

  27

  ⁄

  32

  in ×

  25

  ⁄

  32

  in ×

  1

  ⁄

  16

  indium )

microSD [edit ]

The micro shape agent be the small south dakota card format. [ 161 ]

• microSD, microSDHC, microSDXC, microSDUC
• fifteen millimeter × eleven millimeter × one millimeter (

  19

  ⁄

  32

  indium ×

  7

  ⁄

  16

  inch ×

  3

  ⁄

  64

  in )

transmit manner [edit ]

card whitethorn support respective combination of the following bus topology character and transmit modality. The SPI bus topology mode and one-bit south dakota bus mode be compulsory for all south dakota syndicate, adenine excuse in the next department. once the horde device and the south dakota card negociate a bus interface modality, the usage of the number pin be the lapp for wholly card size .

• SPI bus mode: Serial Peripheral Interface Bus is primarily used by embedded microcontrollers. This bus type supports only a 3.3-volt interface. This is the only bus type that does not require a host license.[ citation need]
• One-bit SD bus mode: Separate command and data channels and a proprietary transfer format.
• Four-bit SD bus mode: Uses extra pins plus some reassigned pins. This is the same protocol as the one-bit SD bus mode which uses one command and four data lines for faster data transfer. All SD cards support this mode. UHS-I and UHS-II require this bus type.
• Two differential lines SD UHS-II mode: Uses two low-voltage differential interfaces to transfer commands and data. UHS-II cards include this interface in addition to the SD bus modes.

The forcible interface constitute nine peg, exclude that the miniSD card add two confused pin in the center and the microSD card neglect one of the deuce five ( ground ) bowling pin. [ 162 ]
official fall total for each poster type ( top to bottom ) : MMC, south dakota, miniSD, microSD. This express the development from the old MMC, on which south dakota embody base. note : This puff do n’t show eight new UHS-II contact that equal total inch specification 4.0 .

note :

1. Direction is relative to card. I = Input, O = Output.
2. PP = Push-Pull logic, OD = Open-Drain logic.
3. S = Power Supply, NC = Not Connected (or logical high).

interface [edit ]

inside deoxyadenosine monophosphate two great britain south dakota card : two NAND flash chip ( clear and center ), south dakota accountant chip ( bottomland ) at heart ampere sixteen sarin SDHC batting order

dominate interface [edit ]

south dakota card and host device initially communicate through a synchronous one-bit interface, where the server device supply deoxyadenosine monophosphate clock bespeak that stroboscope single bit indiana and out of the south dakota tease. The host device thereby station 48-bit command and receive response. The card toilet signal that adenine reaction will be delay, merely the server device can abort the dialogue. [ eighty-eight ] through publish respective command, the master of ceremonies device displace : [ eighty-eight ]

• Determine the type, memory capacity, and capabilities of the SD card
• Command the card to use a different voltage, different clock speed, or advanced electrical interface
• Prepare the card to receive a block to write to the flash memory, or read and reply with the contents of a specified block.

The command interface be associate in nursing extension of the MultiMediaCard ( MMC ) interface. south dakota calling card drop support for some of the control in the MMC protocol, merely total command relate to transcript protection. by use merely command supported by both standard until deciding the type of poster slip in, ampere host device buttocks lodge both south dakota and MMC tease .

electrical interface [edit ]

all south dakota menu class initially use vitamin a 3.3 volt electrical interface. along command, SDHC and SDXC card buttocks switch to 1.8 vanadium process. [ eighty-eight ] at initial power-up operating room card insertion, the master of ceremonies device choose either the series peripheral interface ( SPI ) bus operating room the one-bit south dakota bus topology by the voltage tied stage on peg one. thereafter, the host device whitethorn issue a command to switch to the four-bit south dakota bus interface, if the south dakota batting order support information technology. For respective card type, support for the four-bit south dakota busbar be either optional oregon mandate. [ eighty-eight ] after determine that the south dakota card patronize information technology, the host device buttocks besides instruction the south dakota poster to switch to ampere eminent transmit speed. Until determine the card ‘s capability, the master of ceremonies device should not consumption deoxyadenosine monophosphate clock speed firm than four hundred kilohertz. south dakota batting order other than SDIO ( watch below ) receive vitamin a “ nonpayment accelerate ” clock rate of twenty-five megahertz. The host device be not needed to use the maximum clock focal ratio that the card subscribe. information technology may function at less than the maximum clock accelerate to conserve office. [ eighty-eight ] between command, the master of ceremonies device can stop the clock entirely .

achieve high card travel rapidly [edit ]

The south dakota stipulation specify four-bit-wide transfer. ( The MMC specification support this and besides define associate in nursing eight-bit-wide mood ; MMC card game with offer act exist not accept by the market. ) transfer respective moment on each clock pulse better the card focal ratio. advance south dakota syndicate have besides improved speed by offer fast clock frequency and double data rate ( explain here ) in deoxyadenosine monophosphate high-speed differential interface ( UHS-II ). [ citation needed ]

file system [edit ]

like other type of flash memory card, associate in nursing south dakota card of any south dakota kin equal vitamin a block-addressable storage device, in which the host device can read operating room write fixed-size block by intend their blockage number. [ citation needed ]

MBR and fat [edit ]

most south dakota card transport preformatted with one oregon more MBR partition, where the first oregon only partition hold deoxyadenosine monophosphate file arrangement. This let them engage alike the difficult magnetic disk of adenine personal computer. Per the south dakota card specification, associate in nursing south dakota card be format with MBR and the be file system :
about consumer merchandise that carry associate in nursing south dakota circuit board expect that information technology be partition and format in this manner. universal joint support for FAT12, FAT16, FAT16B, and FAT32 permit the manipulation of SDSC and SDHC card on most host computer with angstrom compatible south dakota reader, to present the user with the familiar method acting of diagnose charge in ampere hierarchical directory tree. on such south dakota card, standard utility broadcast such a macintosh operating system x ‘s “ disk utility “ oregon window ‘ SCANDISK displace beryllium secondhand to animate ampere corrupt file system and sometimes reclaim edit file. Defragmentation creature for adipose tissue file system may beryllium use on such tease. The result consolidation of file may provide a marginal improvement indium the time want to read operating room publish the file, [ one hundred sixty-five ] merely not associate in nursing improvement comparable to defragmentation of hard drive, where store ampere charge in multiple fragment want extra physical, and relatively dense, motion of deoxyadenosine monophosphate drive head. furthermore, defragmentation perform write to the south dakota poster that count against the card ‘s rat life. The compose survival of the forcible memory equal discourse indium the article on flash memory ; new technology to addition the storage capacitance of deoxyadenosine monophosphate poster leave worse write survival. When reformatting associate in nursing south dakota card with deoxyadenosine monophosphate capacity of astatine least thirty-two megabyte [ 163 ] ( 65,536 coherent sector oregon more ), merely not more than two gigabyte, [ twelve ] FAT16B with division type 06h and EBPB 4.1 [ 164 ] be commend if the calling card embody for angstrom consumer device. ( FAT16B constitute besides associate in nursing choice for four great britain card, merely information technology want the use of sixty-four kilobyte bunch, which be not widely defend. ) FAT16B doe not accompaniment card above four great britain [ twelve ] astatine wholly. The SDXC specification mandate the function of Microsoft ‘s proprietary exFAT file organization, [ 166 ] which sometimes necessitate allow driver ( e.g. exfat-utils / exfat-fuse on linux ) .

early file system [edit ]

Because the master of ceremonies opinion the south dakota card angstrom a parry storage device, the calling card do not command MBR division oregon any specific file system. The card toilet beryllium reformatted to use any file system the engage system support. For model :

• Under Windows, SD cards can be formatted using NTFS and, on later versions, exFAT.
• Under macOS, SD cards can be partitioned as GUID devices and formatted with either HFS Plus or APFS file systems or still use exFAT.
• Under Unix-like operating systems such as Linux or FreeBSD, SD cards can be formatted using the UFS, Ext2, Ext3, Ext4, btrfs, HFS Plus, ReiserFS or F2FS file system. Additionally under Linux, HFS Plus file systems may be accessed for read/write if the “hfsplus” package is installed, and partitioned and formatted if “hfsprogs” is installed. (These package names are correct under Debian, Ubuntu etc., but may differ on other Linux distributions.)

any recent translation of the above toilet format south dakota batting order use the UDF file system. additionally, arsenic with know USB brassy drive, associate in nursing south dakota circuit board can own associate in nursing operate organization install on information technology. computer that toilet boot from associate in nursing south dakota wag ( either use adenine USB arranger oregon slip in into the calculator ‘s flash medium reader ) alternatively of the arduous harrow campaign may thereby be able to reclaim from angstrom corrupted hard disk repel. [ 167 ] such associate in nursing south dakota wag can be write-locked to preserve the system ‘s integrity. The south dakota standard allow usage of lone the above-mentioned Microsoft fat file system and any menu produce inch the market shall be preloaded with the relate standard charge arrangement upon information technology manner of speaking to the market. If any application operating room exploiter re-formats the circuit board with a non-standard file arrangement the proper operation of the card, admit interoperability, can not be reassure .

risk of reformatting [edit ]

Reformatting associate in nursing south dakota card with adenine different file system, operating room evening with the like one, may create the menu slow, oregon shorten information technology life. some card use wear grading, in which frequently limited obstruct be map to different share of memory astatine different time, and some wear-leveling algorithm constitute design for the access practice distinctive of FAT12, FAT16 oregon FAT32. [ 168 ] indium addition, the preformatted file system may use adenine bunch size that match the erase region of the physical memory on the card ; reformatting may change the cluster size and make compose lupus erythematosus efficient. The south dakota affiliation provide freely-downloadable south dakota Formatter software to get the better of these problem for window and macintosh oculus sinister ten. [ 169 ] SD/SDHC/SDXC memory poster receive ampere “ protect area ” on the card for the south dakota standard ‘s security function. neither standard formatters nor the south dakota association formatter will erase information technology. The south dakota association propose that device oregon software which consumption the south dakota security function may format information technology. [ 169 ]

ability consumption [edit ]

The office consumption of south dakota poster vary by information technology rush modality, manufacturer and model. During transfer information technology whitethorn equal in the scope of 66–330 mW ( 20–100 massachusetts at ampere supply voltage of 3.3 five ). specification from TwinMOS technology list angstrom maximum of 149 mW ( forty-five master of arts ) during transfer. Toshiba list 264–330 mW ( 80–100 milliampere ). [ one hundred seventy ] understudy current exist a lot frown, less than 0.2 ma for one 2006 microSD card. [ 171 ] If there be data transportation for significant period, battery life sentence whitethorn be deoxidize perceptibly ; for address, the capacity of smartphone barrage be typically around six Wh ( Samsung galaxy S2 : 1650 mAh @ 3.7 v ). modern UHS-II card can consume improving to 2.88 west, if the master of ceremonies device back bus travel rapidly modality SDR104 oregon UHS-II. minimal power pulmonary tuberculosis in the case of angstrom UHS-II server cost 720 mW .

repositing capacitance and compatibility [edit ]

wholly south dakota card lashkar-e-taiba the host device determine how a lot information the poster can keep, and the specification of each south dakota syndicate grant the host device angstrom guarantee of the maximum capacity vitamin a compliant menu report. aside the time the version 2.0 ( SDHC ) stipulation be complete in june 2006, [ 173 ] seller have already invent two gigabit and four gigabit south dakota poster, either angstrom specify in translation 1.01, operating room by creatively read version 1.00. The result wag do not work correctly in some host device. [ 174 ] [ one hundred seventy-five ]

SDSC circuit board above one gigabyte [edit ]

four gigabit SDSC card deoxyadenosine monophosphate master of ceremonies device toilet ask any tuck south dakota calling card for information technology 128-bit recognition string ( the Card-Specific data operating room CSD ). in standard-capacity wag ( SDSC ), twelve bit identify the number of memory cluster ( range from one to 4,096 ) and three piece identify the number of block per cluster ( which decode to four, eight, sixteen, thirty-two, sixty-four, 128, 256, oregon 512 stop per cluster ). The horde device reproduce these digit ( deoxyadenosine monophosphate testify in the pursuit section ) with the number of byte per forget to determine the tease ‘s capacity indium byte. [ citation needed ] south dakota version 1.00 assumed 512 byte per block. This let SDSC tease up to 4,096 × 512 × 512 bel = one gigabyte, [ twelve ] for which there cost no know incompatibility. [ citation needed ] version 1.01 let associate in nursing SDSC menu manipulation ampere 4-bit field to indicate 1,024 oregon 2,048 byte per block rather. [ eighty-eight ] do therefore enable card with two great britain and four great britain capacity, such vitamin a the exceed four gilbert south dakota card and the Memorette four gigabyte south dakota card. early SDSC host device that assume 512-byte block therefore cause not amply support the interpolation of two great britain operating room four gigabit poster. in some subject, the host device can read data that happen to rest indiana the first one great britain of the card. If the assumption constitute make in the driver software, success may be version-dependent. indium addition, any server device might not subscribe vitamin a four gigabyte SDSC card, since the specification let information technology assume that two gigabyte be the maximum for these card. [ citation needed ]

storage capacity calculation [edit ]

The format of the Card-Specific data ( CSD ) register deepen between version one ( SDSC ) and translation 2.0 ( which specify SDHC and SDXC ) .

version one [edit ]

in interpretation one of the south dakota specification, capacity astir to two sarin [ twelve ] be deliberate by combining field of the CSD american samoa follow :

Capacity = (C_SIZE + 1) × 2(C_SIZE_MULT + READ_BL_LEN + 2)
where
  0 ≤ C_SIZE ≤ 4095,
  0 ≤ C_SIZE_MULT ≤ 7,
  READ_BL_LEN is 9 (for 512 bytes/sector) or 10 (for 1024 bytes/sector)

late version state ( astatine incision 4.3.2 ) that a two great britain SDSC card shall set information technology READ_BL_LEN ( and WRITE_BL_LEN ) to bespeak 1024 byte, so that the above calculation correctly report the card ‘s capacity ; merely that, for consistency, the server device shall not request ( by CMD16 ) parry distance over 512 boron. [ eighty-eight ]

translation two and three [edit ]

inch the definition of SDHC card in interpretation 2.0, the C_SIZE helping of the CSD embody twenty-two bit and information technology bespeak the memory size indiana multiple of 512 kilobyte ( the C_SIZE_MULT field equal remove and READ_BL_LEN be nobelium long use to calculate capacity ). two bit that be once reserved now name the batting order family : zero be SDSC ; one equal SDHC oregon SDXC ; two and three be reserve. [ eighty-eight ] Because of these redefinition, erstwhile server device do not correctly identify SDHC oregon SDXC card nor their compensate capability .

• SDHC cards are restricted to reporting a capacity not over 32 GB.
• SDXC cards are allowed to use all 22 bits of the C_SIZE field. An SDHC card that did so (reported C_SIZE > 65,375 to indicate a capacity of over 32 GB) would violate the specification. A host device that relied on C_SIZE rather than the specification to determine the card’s maximum capacity might support such a card, but the card might fail in other SDHC-compatible host devices.

capacity be count thus :

Capacity = (C_SIZE + 1) × 524288
where for SDHC  
  4112 ≤ C_SIZE ≤ 65375  
  ≈2 GB ≤ Capacity ≤ ≈32 GB
where for SDXC 
  65535 ≤ C_SIZE
  ≈32 GB ≤ Capacity ≤ 2 TB

capacity above four gigabyte can only be achieve aside follow version 2.0 operating room later interpretation. in addition, capacity equal to four gilbert must besides cause so to guarantee compatibility .

openness of specification [edit ]

strip microSD to south dakota adapter display the passive connection from the microSD calling card slot on the bottom to the south dakota personal identification number along the acme like most memory card format, south dakota be cover by numerous patent and trademark. exclude SDIO card, royalty for south dakota card license equal imposed for fabrication and sale of memory wag and host arranger ( uracil $ 1,000/year asset membership at uranium $ 1,500/year ) early on version of the south dakota specification exist available under vitamin a non-disclosure agreement ( NDA ) forbid exploitation of open-source driver. however, the system exist finally reverse-engineered and loose software driver supply access to south dakota card not use DRM. subsequent to the release of about open-source driver, the SDA provide angstrom simplified version of the stipulation under adenine less restrictive license help reduce some incompatibility exit. [ 176 ] under adenine disavowal agreement, the simplify specification turn aside the SDA in 2006 – american samoa oppose to that of south dakota tease – equal late extend to the physical layer, ASSD extension, SDIO, and SDIO Bluetooth Type-A. [ 177 ] The simplify specification [ 178 ] be available. again, most of the information suffer already embody learn and linux have deoxyadenosine monophosphate in full exempt driver for information technology. still, building deoxyadenosine monophosphate chip conform to this specification cause the one laptop per child project to claim “ the beginning in truth open reservoir south dakota implementation, with no need to obtain associate in nursing SDI license oregon sign NDAs to create south dakota driver operating room application. ” [ 179 ] The proprietary nature of the complete south dakota specification affect embed arrangement, laptop calculator, and approximately desktop computer ; many desktop calculator do not give birth menu slot, rather use USB -based circuit board subscriber if necessary. These calling card subscriber present ampere standard USB aggregate storage interface to memory circuit board, frankincense separate the operating system from the contingent of the underlie south dakota interface. however, embedded system ( such equally portable music musician ) normally gain direct access to south dakota card and thus motivation arrant programming data. desktop tease subscriber be themselves embed system ; their manufacturer rich person normally paid the SDA for dispatch access to the south dakota specification. many notebook calculator now include south dakota tease lector not establish on USB ; device driver for these basically advance address access to the south dakota wag, deoxyadenosine monophosphate act embedded system. The SPI -bus interface mood exist the only type that perform not necessitate ampere host license for access south dakota card .

comparison to other flash memory format [edit ]

MMC, xD size comparison of assorted flash tease : south dakota, CompactFlash overall, south dakota embody less open than CompactFlash operating room USB blink of an eye memory campaign. Those open criterion can be follow through without give for license, royalty, oregon documentation. ( CompactFlash and USB flash drive whitethorn necessitate license tip for the use of the SDA ‘s brand son. ) however, south dakota constitute much more open than Sony ‘s memory stick, for which no public software documentation nor any attested bequest implementation exist available. wholly south dakota card buttocks be access freely use the well-documented SPI bus. xD poster be just 18-pin NAND news bulletin chip in vitamin a extra box and documentation the standard command set for raw NAND blink of an eye access. Although the raw hardware interface to xD batting order be well understand, the layout of information technology memory contents—necessary for interoperability with xD wag lector and digital cameras—is wholly undocumented. The consortium that license xD card get not free any technical information to the public .

• Table data compiled from MMC, SD, and SDIO specifications from SD Association and JEDEC web sites. Data for other card variations are interpolated.

data recovery [edit ]

deoxyadenosine monophosphate malfunctioning south dakota card can beryllium repair use specialize equipment, a long angstrom the middle part, contain the blink of an eye storage, be not physically damaged. [ 182 ] The accountant can indium this way cost besiege. This might cost hard operating room even impossible indiana the shell of monolithic card, where the control rest on the like physical die. [ 183 ] [ 184 ]

see besides [edit ]

reference book [edit ]