SD (top), miniSD, microSD cards Media type Capacity SDSC (SD): 1 MB to 2 GB, some 4 GB were made SDHC. Contents • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Overview [ ] Secure Digital includes four card families available in three different sizes. The four families are the original Standard-Capacity (SDSC), the High-Capacity (SDHC), the eXtended-Capacity (), and the, which combines functions with data storage. The are the original size, the mini size, and the micro size. Electrically passive adapters allow a smaller card to fit and function in a device built for a larger card.

You can download and update all SDA Standard Compliant SD Host Controller drivers for free on this page. Choose a proper version according to your system information and click download button to quickly download the needed driver. Download the latest drivers for your Dell Inspiron 1501 to keep your Computer up-to-date.

The SD card's small footprint is an ideal storage medium for smaller, thinner and more portable electronic devices. SD (SDSC) [ ]. This section does not any.

Unsourced material may be challenged and. (October 2016) () The second-generation Secure Digital (SDSC or Secure Digital Standard Capacity) card was developed to improve on the (MMC) standard, which continued to evolve, but in a different direction.

Secure Digital changed the MMC design in several ways: • Asymmetrical shape of the sides of the SD card prevent inserting it upside down (while an MMC goes in most of the way but makes no contact if inverted). • Most SD cards are 2.1 mm (0.083 inches) 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, 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. • 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 (CPRM) security circuitry for (DRM) content-protection.

• Addition of a write-protect notch Full-size SD cards do not fit into the slimmer MMC slots, and other issues also affect the ability to use one format in a host device designed for the other. Official SDHC logo The Secure Digital High Capacity (SDHC) format, announced in January 2006 and defined in version 2.0 of the SD specification, supports cards with capacities up to 32 GB. The SDHC trademark is licensed to ensure compatibility. SDHC cards are physically and electrically identical to standard-capacity SD cards (SDSC). The major compatibility issues between SDHC and SDSC cards are the redefinition of the Card-Specific Data (CSD) register in version 2.0 (see ), and the fact that SDHC cards are shipped preformatted with the file system. Version 2.0 also introduces a High-speed bus mode for both SDSC and SDHC cards, which doubles the original Standard Speed clock to produce 25. SDHC host devices are required to accept older SD cards.

However, older host devices do not recognize SDHC or SDXC memory cards, although some devices can do so through a firmware upgrade. Older Windows operating systems released before Windows 7 require patches or service packs to support access to SDHC cards. Official SDXC logo The Secure Digital eXtended Capacity (SDXC) format, announced in January 2009 and defined in version 3.01 of the SD specification, supports cards up to 2 TB (2048 GB), compared to a limit of 32 GB for SDHC cards in the SD 2.0 specification. SDXC adopts Microsoft's file system as a mandatory feature. Version 3.01 also introduced the for both SDHC and SDXC cards, with interface speeds from 50 MByte/s to 104 MByte/s for four-bit UHS-I bus. Version 4.0, introduced in June 2011, allows speeds of 156 MByte/s to 312 MByte/s over the four-lane (two differential lanes) UHS-II bus, which requires an additional row of physical pins. Version 5.0 was announced in February 2016 at CP+ 2016, and added 'Video Speed Class' ratings for UHS cards to handle higher resolution video formats like.

The new speed ratings go up to 90 MB/s. ExFAT filesystem [ ]. This section needs additional citations for. Unsourced material may be challenged and removed.

(October 2016) () SDXC cards utilize the file system, the use of which is governed by a proprietary license, thereby limiting its legal availability to a small set of operating systems. Therefore, exFAT-formatted SDXC cards are not a universally readable exchange medium. (SP1) and later and (10.6.5 and later) support exFAT out of the box. (Windows XP and Server 2003 can support exFAT via an optional update from Microsoft.) Most and distributions do not, for legal reasons; users must manually install third-party implementations of exFAT (as a module) in order to be able to mount exFAT-formatted volumes. However, SDXC cards can be reformatted to use any file system (such as,, or ), alleviating the restrictions associated with exFAT availability. Nevertheless, in order to be fully compliant with the SDXC card specification, many SDXC-capable host devices are firmware-programmed to expect exFAT on cards larger than 32 GB [ ].

Download Uc Browser For Java 320x240. Consequently, they may not accept SDXC cards reformatted as FAT32, even if the device supports FAT32 on smaller cards (for SDHC compatibility). Therefore, even if a file system is supported in general, it is not always possible to use alternative file systems on SDXC cards at all depending on how strictly the SDXC card specification has been implemented in the host device.

This bears a risk of accidental loss of data, as a host device may treat a card with an unrecognized file system as blank or damaged and. The SD Association provides a formatting utility for Windows and Mac OS X that checks and formats SD, SDHC, and SDXC cards. Ultra High Speed (UHS) bus [ ]. Back side of a Lexar UHS-II microSDHC card, showing the additional row of UHS-II connections The Ultra High Speed (UHS) bus is available on some SDHC and SDXC cards. The following ultra-high speeds are specified: UHS-I Specified in SD version 3.01, supports a clock frequency of 100 MHz (a quadrupling of the original 'Default Speed'), which in four-bit transfer mode could transfer 50 MB/s (SDR50). UHS-I cards declared as UHS104 (SDR104) also support a clock frequency of 208 MHz, which could transfer 104 MB/s. Operation at 50 MHz (DDR50) is also specified in Version 3.01, and is mandatory for microSDHC and microSDXC cards labeled as UHS-I.

In this mode, four bits are transferred when the clock signal rises and another four bits when it falls, transferring an entire byte on each full clock cycle, hence a 50 MB/s operation could be transferred using a 50 MHz clock. UHS-II Specified in version 4.0, further raises the data transfer rate to a theoretical maximum of 156 MB/s (full ) or 312 MB/s (half duplex) using an additional row of pins (a total of 17 pins for full-size and 16 pins for micro-size cards). UHS-III Version 6.0, released in February 2017, added two new data rates to the standard. FD312 provides 312 MB/s while FD624 doubles that.

Both are full-duplex. The physical interface and pin-layout are the same as with UHS-II, retaining backward compatibility. Cards that comply with UHS show Roman numerals 'I', 'II' or 'III' next to the SD card logo, and report this capability to the host device. Use of UHS-I requires that the host device command the card to drop from 3.3-volt to 1.8-volt operation over the I/O interface pins and select the four-bit transfer mode, while UHS-II requires 0.4-volt operation. The higher speed rates are achieved by using a two-lane low voltage (0.4 V pp) differential interface. Each lane is capable of transferring up to 156 MB/s. In full duplex mode, one lane is used for Transmit while the other is used for Receive.

In half duplex mode both lanes are used for the same direction of data transfer allowing a double data rate at the same clock speed. In addition to enabling higher data rates, the UHS-II interface allows for lower interface power consumption, lower I/O voltage and lower electromagnetic interference (EMI). Speeds [ ] SD card speed is customarily rated by its sequential read or write speed. The sequential performance aspect is the most relevant for storing and retrieving large files (relative to block sizes internal to the ), such as images and multimedia. Small data (such as file names, sizes and timestamps) falls under the much lower, which can be the limiting factor in some use cases. With early SD cards, a few card manufacturers specified the speed as a 'times' ('×') rating, which compared the average speed of reading data to that of the original drive.

This was superseded by the Speed Class Rating, which guarantees a minimum rate at which data can be written to the card. The newer families of SD card improve card speed by increasing the bus rate (the frequency of the clock signal that strobes information into and out of the card). Whatever the bus rate, the card can signal to the host that it is 'busy' until a read or a write operation is complete. Compliance with a higher speed rating is a guarantee that the card limits its use of the 'busy' indication. Bus interface Card logo Bus logo Bus speed Spec version Default Speed — 12.5 MByte/s 1.01 High Speed 25 MByte/s 2.00 UHS-I 12.5 MByte/s (SDR12) 25 MByte/s (SDR25) 50 MByte/s (SDR50, DDR50) 104 MByte/s (SDR104) 3.01 UHS-II 156 MByte/s (FD156) 312 MByte/s (HD312) 4.00/4.10 UHS-III 312 MByte/s (FD312) 624 MByte/s (FD624) 6.0 Speed class rating [ ].

Main article: The '×' rating, that was used by some card manufacturers and made obsolete by speed classes, is a multiple of the standard drive speed of 150 (approximately 1.23 ). Basic cards transfer data at up to six times (6×) the CD-ROM speed; that is, 900 KiB/s or 7.37 Mbit/s. The 2.0 specification [ ] defines speeds up to 200×, but is not as specific as Speed Classes are on how to measure speed. Manufacturers may report best-case speeds and may report the card's fastest read speed, which is typically faster than the write speed. Some vendors, including and, report their cards' write speed. When a card lists both a speed class and an '×' rating, the latter may be assumed a read speed only. Real-world performance [ ] In applications that require sustained write throughput, such as video recording, the device might not perform satisfactorily if the SD card's class rating falls below a particular speed.

For example, a high-definition may require a card of not less than Class 6, suffering dropouts or corrupted video if a slower card is used. With slow cards may take a noticeable time after taking a photograph before being ready for the next, while the camera writes the first picture. The speed class rating does not totally characterize card performance. Different cards of the same class may vary considerably while meeting class specifications. A card's speed depends on many factors, including: • The frequency of soft errors that the card's controller must re-try •: 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. •: 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, 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. In addition, speed may vary markedly between writing a large amount of data to a single file (, as when a records large photographs or videos) and writing a large number of small files (a use common in ). A study in 2012 found that, in this random-access use, some Class 2 cards achieved a write speed of 1.38, while all cards tested of Class 6 or greater (and some of lower Classes; lower Class does not necessarily mean better small-file performance), including those from major manufacturers, were over 100 times slower.

In 2014, a blogger measured a 300-fold performance difference on small writes; this time, the best card in this category was a class 4 card. Features [ ] Card security [ ] Cards can protect their contents from erasure or modification, prevent access by non-authorized users, and protect copyrighted content using digital rights management. [ ] Commands to disable writes [ ]. Unlocked and locked SD cards The user can designate most full-size SD cards as read-only by use of a sliding tab that covers a notch in the card.

The miniSD and microSD formats do not support a write protection notch. When looking at the SD card from the top, the right side (the side with the beveled corner) must be notched. On the left side, there may be a write-protection notch.

If the notch is omitted, the card can be read and written. If the card is notched, it is read-only. If the card has a notch and a sliding tab which covers the notch, the user can slide the tab upward (toward the contacts) to declare the card read/write, or downward to declare it read-only. The diagram to the right shows an orange sliding write-protect tab in both the unlocked and locked positions.

The presence of a notch, and the presence and position of a tab, have no effect on the SD card's operation. A host device that supports write protection should refuse to write to an SD card that is designated read-only in this way. Some host devices do not support write protection, which is an optional feature of the SD specification. Drivers and devices that do obey a read-only indication may give the user a way to override it.

Cards sold with content that must not be altered are permanently marked read-only by having a notch and no sliding tab. Card password [ ]. MicroSD to SD adapter (left), microSD to miniSD adapter (middle), microSD card (right) A host device can lock an SD card using a password of up to 16 bytes, typically supplied by the user. A locked card interacts normally with the host device except that it rejects commands to read and write data. A locked card can be unlocked only by providing the same password. The host device can, after supplying the old password, specify a new password or disable locking.

Without the password (typically, in the case that the user forgets the password), the host device can command the card to erase all the data on the card for future re-use (except card data under DRM), but there is no way to gain access to the existing data. Devices use SD cards designed for access only by the phone manufacturer or mobile provider. An SD card inserted into the phone underneath the battery compartment becomes locked 'to the phone with an automatically generated key' so that 'the SD card cannot be read by another phone, device, or PC'.

Devices, however, are some of the few that can perform the necessary low-level format operations on locked SD cards. It is therefore possible to use a device such as the to reformat the card for subsequent use in other devices. SmartSD cards [ ] A smartSD memory card is a microSD card with an internal 'secure element' that allows the transfer of ISO 7816 commands to, for example, applets running on the internal secure element through the SD bus. Various implementations of smartSD cards have been done for payment applications and secured authentication.

MicroSD cards with Secure Element and NFC () support are used for payment and secure access. Vendor enhancements [ ]. SD cards with dual interfaces: SD and Vendors have sought to differentiate their products in the market through various vendor-specific features: • Integrated – 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: /,,,, and. Some models their pictures. • Pre-loaded content – In 2006, SanDisk announced, 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 name, this time not using any of the DRM capabilities of the SD card. In 2011, SanDisk offered various collections of 1000 songs on a single slotMusic card for about $40, now restricted to compatible devices and without the ability to copy the files.

• Integrated USB connector – The SD Plus product can be plugged directly into a port without needing a USB card reader. 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. SDIO cards [ ]. Camera using the SDIO interface to connect to some HP iPAQ devices A SDIO (Secure Digital Input Output) card is an extension of the SD specification to cover I/O functions. SDIO cards are only fully functional in host devices designed to support their input-output functions (typically PDAs like the, but occasionally laptops or mobile phones). These devices can use the SD slot to support receivers,,, tuners, TV tuners, readers,, and interfaces to,,, and.

Many other SDIO devices have been proposed, but it is now more common for I/O devices to connect using the USB interface. SDIO cards support most of the memory commands of SD cards. SDIO cards can be structured as eight logical cards, although currently, the typical way that an SDIO card uses this capability is to structure itself as one I/O card and one memory card.

The SDIO and SD interfaces are mechanically and electrically identical. Host devices built for SDIO cards generally accept SD memory cards without I/O functions. However, the reverse is not true, because host devices need suitable drivers and applications to support the card's I/O functions. For example, an HP SDIO camera usually does not work with PDAs that do not list it as an accessory. Inserting an SDIO card into any SD slot causes no physical damage nor disruption to the host device, but users may be frustrated that the SDIO card does not function fully when inserted into a seemingly compatible slot.

(USB and Bluetooth devices exhibit comparable compatibility issues, although to a lesser extent thanks to standardized and.) The family comprises Low-Speed and Full-Speed cards. Both types of SDIO cards support SPI and one-bit SD bus types. Low-Speed SDIO cards are allowed to also support the four-bit SD bus; Full-Speed SDIO cards are required to support the four-bit SD bus. To use an SDIO card as a 'combo card' (for both memory and I/O), the host device must first select four-bit SD bus operation.

Two other unique features of Low-Speed SDIO are a maximum clock rate of 400 kHz for all communications, and the use of Pin 8 as 'interrupt' to try to initiate dialogue with the host device. Ganging cards together The one-bit SD protocol was derived from the MMC protocol, which envisioned the ability to put up to three cards on a bus of common signal lines. The cards use interfaces, where a card may pull a line to the low voltage level; the line is at the high voltage level (because of a ) if no card pulls it low. Though the cards shared clock and signal lines, each card had its own line to sense that the host device had selected it. [ ] The SD protocol envisioned the ability to gang 30 cards together without separate chip select lines.

The host device would broadcast commands to all cards and identify the card to respond to the command using its unique serial number. [ ] In practice, cards are rarely ganged together because open-collector operation has problems at high speeds and increases power consumption. Newer versions of the SD specification recommend separate lines to each card. [ ] Compatibility [ ] Host devices that comply with newer versions of the specification provide and accept older SD cards. For example, SDXC host devices accept all previous families of SD memory cards, and SDHC host devices also accept standard SD cards.

Older host devices generally do not support newer card formats, and even when they might support the bus interface used by the card, there are several factors that arise: • A newer card may offer than the host device can handle (over 4 GB for SDHC, over 32 GB for SDXC). • A newer card may use a the host device cannot navigate ( for SDHC, 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 ) and 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. • Some vendors produced SDSC cards above 1GB before the SDA had standardized a method of doing so. SD compatibility table SDSC card SDHC card SDHC UHS card SDXC card SDXC UHS card SDIO card SDSC slot Yes No No No No No SDHC slot Yes Yes Yes No No No SDHC UHS slot Yes Yes Yes No No No SDXC slot Yes Yes Yes Yes Yes No SDXC UHS slot Yes Yes Yes Yes Yes No SDIO slot Varies Varies Varies Varies Varies Yes. This microSDHC card holds 8 billion bytes. Beneath it is a section of a (used until the 1970s) that holds eight bytes using 64 cores.

The SD card has a capacity one billion times larger. In 1999,,, and agreed to develop and market the Secure Digital (SD) Memory Card.

The card was derived from the (MMC) and provided digital rights management based on the (SDMI) standard and for the time, a high memory density. It was designed to compete with the, a DRM product that had released the year before. Developers predicted that DRM would induce wide use by music suppliers concerned about piracy. The SD was originally developed for the, which was the unsuccessful Toshiba entry in the.

For this reason the D within the logo resembles an optical disc. At the 2000 (CES) trade show, the three companies announced the creation of the SD Association (SDA) to promote SD cards. The SD Association, headquartered in San Ramon, California, United States, started with about 30 companies and today consists of about 1,000 product manufacturers that make interoperable memory cards and devices.

Early samples of the SD Card became available in the first quarter of 2000, with production quantities of 32 and 64 cards available three months later. Mini- and micro-cards [ ] The miniSD form was introduced at March 2003 by Corporation which announced and demonstrated it. The SDA adopted the miniSD card in 2003 as a small form factor extension to the SD card standard. While the new cards were designed especially for mobile phones, they are usually packaged with a miniSD adapter that provides compatibility with a standard SD memory card slot.

In September 2006, SanDisk announced the 4 GB miniSDHC. Like the SD and SDHC, the miniSDHC card has the same form factor as the older miniSD card but the HC card requires HC support built into the host device. Devices that support miniSDHC work with miniSD and miniSDHC, but devices without specific support for miniSDHC work only with the older miniSD card. Since 2008, miniSD cards were no longer produced. The microSD removable miniaturized Secure Digital flash memory cards were originally named T-Flash or TF, abbreviations of TransFlash. TransFlash and microSD cards are functionally identical allowing either to operate in devices made for the other.

SanDisk had conceived microSD when its and the chief technology officer of concluded that current memory cards were too large for. The card was originally called T-Flash, but just before product launch, T-Mobile sent a order to SanDisk claiming that T-Mobile owned the trademark on T-(anything), [ ] and the name was changed to TransFlash. At CTIA Wireless 2005, the SDA announced the small microSD form factor along with SDHC secure digital high capacity formatting in excess of 2 GB with a minimum sustained read and write speed of 17.6 Mbit/s. SanDisk induced the SDA to administer the microSD standard. The SDA approved the final microSD specification on July 13, 2005. Initially, microSD cards were available in capacities of 32, 64, and 128 MB.

The Motorola E398 was the first mobile phone to contain a TransFlash (later microSD) card. A few years later, their competitors began using microSD cards.

SDIO, SDHC, and SDXC [ ] In April 2006, the SDA released a detailed specification for the non-security related parts of the SD memory card standard and for the Secure Digital Input Output (SDIO) cards and the standard SD host controller. [ ] The SDHC format, announced in January 2006, brought improvements such as 32 GB storage capacity and mandatory support for filesystems. [ ] In January 2009, the SDA announced the SDXC family, which supports cards up to 2 TB and speeds up to 300 MB/s.

[ ] It features mandatory support for the filesystem. [ ] SDXC was announced at (CES) 2009 (January 7–10, 2009).

At the same show, and also announced a comparable variant with the same 2 TB maximum as SDXC, and announced plans to produce 64 GB SDXC cards. On March 6, 2009, Pretec introduced the first SDXC card, a 32 GB card with a read/write speed of 400 Mbit/s. But only early in 2010 did compatible host devices come onto the market, including 's HDR-CX55V, 's (also known as Rebel T2i) Digital SLR camera, a USB card reader from Panasonic, and an integrated SDXC card reader from JMicron. The earliest laptops to integrate SDXC card readers relied on a USB 2.0 bus, which does not have the bandwidth to support SDXC at full speed.

Also in early 2010, commercial SDXC cards appeared from (64 GB), Panasonic (64 GB and 48 GB), and SanDisk (64 GB). In early 2011, (64 GB and 128 GB) and (128 GB) began shipping SDXC cards rated at Speed Class 10. Pretec offered cards from 8 GB to 128 GB rated at Speed Class 16. In September 2011, SanDisk released a 64 GB microSDXC card.

Kingmax released a comparable product in 2011. In late 2012, Lexar released the first 256 GB SDXC card, based on 20 nm technology. In April 2012, Panasonic introduced card format for professional video applications. The cards are essentially full-size SDHC or SDXC cards, rated at UHS Speed Class U1. An adapter allows MicroP2 cards to work in current equipment. Panasonic MicroP2 cards shipped in March 2013 and were the first UHS-II compliant products on market; initial offer includes a 32GB SDHC card and a 64GB SDXC card. In February 2014, SanDisk introduced the first 128 GB microSDXC card, which was followed by a 200 GB microSDXC card in March 2015.

September 2014 saw SanDisk announce the first 512 GB SDXC card. Samsung announced the world's first EVO Plus 256 GB microSDXC card in May 2016. And in September 2016 announced that a prototype of the first 1 TB SDXC card will be demonstrated. In August 2017, SanDisk launched a 400 GB microSDXC card.

Markets [ ] Secure Digital cards are used in many consumer electronic devices, and have become a widespread means of storing several gigabytes of data in a small size. [ ] Devices in which the user may remove and replace cards often, such as,, and, tend to use full-sized cards. [ ] Devices in which small size is paramount, such as, tend to use microSD cards. [ ] The microSD card has helped propel the smartphone market by giving both manufacturers and consumers greater flexibility and freedom. [ ] Due to their compact size, microSD cards are used in many [ ] different applications in a large variety [ ] of markets. Action cameras, such as the GoPRO's Hero and cameras in drones, frequently use microSD cards.

[ ] Latest versions of major operating systems, including Windows Mobile and Android Marshmallow, allow applications to run from microSD cards creating possibilities for new usage models for SD cards in mobile computing markets. SD cards are not the most economical solution in devices that need only a small amount of non-volatile memory, such as station presets in small radios. They may also not present the best choice for applications that require higher storage capacities or speeds as provided by other flash card standards such as. These limitations may be addressed by evolving memory technologies, such as the world's highest capacity SanDisk Ultra 200GB Micro SD released in 2015. 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, occurs.

Also used for 64 GB fakes. Many personal computers of all types, including tablets and mobile phones, use SD cards, either through built-in slots or through an active electronic adaptor.

Adaptors exist for the, ExpressBus,,, and the. Active adaptors also let SD cards be used in devices designed for other formats, such as. The adaptor lets SD cards be used in a drive.

Counterfeits [ ]. This section needs additional citations for. Unsourced material may be challenged and removed. (October 2016) () SD/MMC cards replaced 's as the dominant memory card format used in digital cameras.

In 2001, SmartMedia had achieved nearly 50% use, but, by 2005, SD/MMC had achieved over 40% of the digital camera market and SmartMedia's share had plummeted by 2007. At this time, all the leading digital camera manufacturers used SD in their consumer product lines, including,,,,,,,,,,, and. Formerly, and used (xD cards) exclusively, while only used; by early 2010 all three supported SD. Some and professional digital cameras continued to offer (CF), either on a second card slot or as the only storage, as CF supports much higher maximum capacities and historically was cheaper for the same capacity. Secure Digital memory cards can be used in Sony EX with an adapter and in Panasonic equipment with a adapter. Personal computers [ ] Although many accommodate SD cards as an auxiliary storage device through a built-in slot or a USB adaptor, SD cards cannot be used as the primary through the onboard controller because none of the SD card variants support ATA signalling.

This use requires a separate SD controller chip or an SD-to-CompactFlash converter. However, on computers that support from a USB interface, an SD card in a USB adaptor can be the primary hard disk, provided it contains an operating system that supports USB access once the bootstrap is complete. Since late 2009, newer computers with installed SD card readers have been able to boot in from SD storage devices, when properly formatted to file format and the default partition table set to. Embedded systems [ ].

A shield () that gives prototyping microprocessors access to SD cards In 2008, the SDA specified Embedded SD, 'leverag[ing] well-known SD standards' to enable non-removable SD-style devices on printed circuit boards. However this standard was not adopted by the market while the MMC standard became the de facto standard for embedded systems. SanDisk provides such embedded memory components under the iNAND brand. Most modern have built-in logic that can interface to an SD card operating in its SPI mode, providing non-volatile storage. Even if a microcontroller lacks the SPI feature, the feature can be emulated. For example, a home-brew combines spare (GPIO) pins of the processor of the router with MMC support code from the. This technique can achieve throughput of up to 1.6.

Technical details [ ] Physical size [ ] The SD card specification defines three physical sizes. The SD and SDHC families are available in all three sizes, but the SDXC family is not available in the mini size, and the SDIO family is not available in the micro size. Smaller cards are usable in larger slots through use of a passive adapter. Standard size [ ]. Size comparison of families: SD (blue), miniSD (green), microSD (red) • SD (SDSC), SDHC, SDXC, SDIO • 32.0×24.0×2.1 mm (1.260×0.945×0.083 in) • 32.0×24.0×1.4 mm (1.260×0.945×0.055 in) (as thin as MMC) for Thin SD (rare) Mini size [ ] • miniSD, miniSDHC, miniSDIO • 21.5×20.0×1.4 mm (0.846×0.787×0.055 in) Micro size [ ] The micro form factor is the smallest SD card format.

• microSD, microSDHC, microSDXC • 15.0×11.0×1.0 mm (0.591×0.433×0.039 in) Transfer modes [ ] Cards may support various combinations of the following bus types and transfer modes. The SPI bus mode and one-bit SD bus mode are mandatory for all SD families, as explained in the next section. Once the host device and the SD card negotiate a bus interface mode, the usage of the numbered pins is the same for all card sizes. • SPI bus mode: is primarily used by embedded. This bus type supports only a 3.3-volt interface. This is the only bus type that does not require a host license.

• 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.

Download Shin Megami Tensei Nocturne Ps2 Iso Torrent. 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 physical interface comprises 9 pins, except that the miniSD card adds two unconnected pins in the center and the microSD card omits one of the two V SS (Ground) pins. Official pin numbers for each card type (top to bottom):, SD, miniSD, microSD. This shows the evolution from the older MMC, on which SD is based. NOTE: This drawing doesn't show 8 new UHS-II contacts that were added in spec 4.0. SPI bus mode pin SD pin miniSD pin microSD pin Name I/O Logic Description 1 1 1 2 nCS I PP SPI Card Select [CS] (Negative logic) 2 2 2 3 DI I PP SPI Serial Data In [MOSI] 3 3 3 VSS S S Ground 4 4 4 4 VDD S S Power 5 5 5 5 CLK I PP SPI Serial Clock [SCLK] 6 6 6 6 VSS S S Ground 7 7 7 7 DO O PP SPI Serial Data Out [MISO] 8 8 8 NC nIRQ. OD Unused (memory cards) Interrupt (SDIO cards) (negative logic) 9 9 1 NC.. Unused 10 NC..

Reserved 11 NC.. Reserved One-bit SD bus mode pin SD pin miniSD pin microSD pin Name I/O Logic Description 1 1 1 2 CD I/O. Card detection (by host), and non-SPI mode detection (by card) 2 2 2 3 CMD I/O PP, OD Command, Response 3 3 3 VSS S S Ground 4 4 4 4 VDD S S Power 5 5 5 5 CLK I PP Serial clock 6 6 6 6 VSS S S Ground 7 7 7 7 DAT0 I/O PP SD Serial Data 0 8 8 8 NC nIRQ.

OD Unused (memory cards) Interrupt (SDIO cards) (negative Logic) 9 9 1 NC.. Unused 10 NC.. Reserved 11 NC.. Reserved Four-bit SD bus mode pin SD pin miniSD pin microSD pin Name I/O Logic Description. 1 1 2 DAT3 I/O PP SD Serial Data 3. 2 2 3 CMD I/O PP, OD Command, Response.

3 3 VSS S S Ground. 4 4 4 VDD S S Power. 5 5 5 CLK I PP Serial clock. 6 6 6 VSS S S Ground.

7 7 7 DAT0 I/O PP SD Serial Data 0 8 8 8 DAT1 nIRQ I/O O PP OD SD Serial Data 1 (memory cards) Interrupt Period (SDIO cards share pin via protocol) 9 9 1 DAT2 I/O PP SD Serial Data 2 10 NC.. Reserved 11 NC.. Reserved Notes: • Direction is relative to card. I = Input, O = Output. • PP = logic, OD = logic.

• S =, NC = Not Connected (or ). Interface [ ]. Inside a 16 GB SDHC card Command interface [ ] SD cards and host devices initially communicate through a one-bit interface, where the host device provides a clock signal that strobes single bits in and out of the SD card. The host device thereby sends 48-bit commands and receives responses. The card can signal that a response will be delayed, but the host device can abort the dialogue. Through issuing various commands, the host device can: • 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 is an extension of the (MMC) interface.

SD cards dropped support for some of the commands in the MMC protocol, but added commands related to copy protection. By using only commands supported by both standards until determining the type of card inserted, a host device can accommodate both SD and MMC cards. Electrical interface [ ] All SD card families initially use a 3.3 electrical interface. On command, SDHC and SDXC cards can switch to 1.8 V operation.

At initial power-up or card insertion, the host device selects either the Serial Peripheral Interface (SPI) bus or the one-bit SD bus by the voltage level present on Pin 1. Thereafter, the host device may issue a command to switch to the four-bit SD bus interface, if the SD card supports it.

For various card types, support for the four-bit SD bus is either optional or mandatory. After determining that the SD card supports it, the host device can also command the SD card to switch to a.

Until determining the card's capabilities, the host device should not use a clock speed faster than 400 kHz. SD cards other than SDIO (see below) have a 'Default Speed' clock rate of 25 MHz. The host device is not required to use the maximum clock speed that the card supports. It may operate at less than the maximum clock speed to conserve power. Between commands, the host device can stop the clock entirely. Achieving higher card speeds [ ] The SD specification defines four-bit-wide transfers.

(The MMC specification supports this and also defines an eight-bit-wide mode; MMC cards with extended bits were not accepted by the market.) Transferring several bits on each clock pulse improves the card speed. Advanced SD families have also improved speed by offering faster clock frequencies and double data rate (explained ) in a high-speed differential interface (UHS-II). [ ] File system [ ] Like other types of card, an SD card of any SD family is a, in which the host device can read or write fixed-size blocks by specifying their block number. [ ] MBR and FAT [ ] Most SD cards ship preformatted with one or more, where the first or only partition contains a. This lets them operate like the of a. This section needs additional citations for. Unsourced material may be challenged and removed.

(November 2016) () Because the host views the SD card as a block storage device, the card does not require MBR partitions or any specific file system. The card can be reformatted to use any file system the operating system supports. For example: • Under, SD cards can be formatted using and, on later versions,. • Under, SD cards can be partitioned as devices and formatted with either or file systems or still use.

• Under operating systems such as or, SD cards can be formatted using the,,,,,, or file system. Additionally under Linux, 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 version of the above can format SD cards using the file system. Additionally, as with flash drives, an SD card can have an operating system installed on it. Computers that can from an SD card (either using a USB adapter or inserted into the computer's flash media reader) instead of the hard disk drive may thereby be able to recover from a corrupted hard disk drive. Such an SD card can be to preserve the system's integrity. The SD Standard allows usage of only the above-mentioned Microsoft FAT file systems and any card produced in the market shall be preloaded with the related standard file system upon its delivery to the market.

If any application or user re-formats the card with a non-standard file system the proper operation of the card, including interoperability, cannot be assured. Risks of reformatting [ ] Reformatting an SD card with a different file system, or even with the same one, may make the card slower, or shorten its lifespan. Some cards use, in which frequently modified blocks are mapped to different portions of memory at different times, and some wear-leveling algorithms are designed for the access patterns typical of FAT12, FAT16 or FAT32. In addition, the preformatted file system may use a cluster size that matches the erase region of the physical memory on the card; reformatting may change the cluster size and make writes less efficient. SD/SDHC/SDXC memory cards have a 'Protected Area' on the card for the SD standard's security function; a standard formatter may erase it, causing problems if security is used. The SD Association provides freely-downloadable SD Formatter software to overcome these problems for Windows and Mac OS X. The SD Formatter does not format the 'Protected Area', and the Association recommends the use of appropriate application software or SD-compatible device that provides SD security function to format the 'Protected Area' in the memory card.

Power consumption [ ] The power consumption of SD cards varies by its speed mode, manufacturer and model. During transfer it may be in the range of 66–330 mW (20–100 mA at a supply voltage of 3.3 V). Specifications from TwinMos technologies list a maximum of 149 mW (45 mA) during transfer. Toshiba lists 264–330 mW (80–100 mA). Standby current is much lower, less than 0.2 mA for one 2006 microSD card. If there is data transfer for significant periods, battery life may be reduced noticeably (smartphones typically have batteries of capacity around 6 Wh (Samsung Galaxy S2, 1650 mAh @ 3.7 V)). Modern UHS-II cards can consume up to 2.88 W, if the host device supports bus speed mode SDR104 or UHS-II.

Minimum power consumption in the case of a UHS-II host is 0.72 W. Card requirements regarding bus speed modes Bus speed mode *1 Max. Bus speed [MB/s] Max. 4 GB SDSC card A host device can ask any inserted SD card for its 128-bit identification string (the Card-Specific Data or CSD). In standard-capacity cards (SDSC), 12 bits identify the number of memory clusters (ranging from 1 to 4,096) and 3 bits identify the number of blocks per cluster (which decode to 4, 8, 16, 32, 64, 128, 256, or 512 blocks per cluster). The host device multiplies these figures (as shown in the following section) with the number of bytes per block to determine the card's capacity in bytes.

[ ] SD version 1.00 assumed 512 bytes per block. This permitted SDSC cards up to 4,096 × 512 × 512 = 1 GB, for which there are no known incompatibilities.

[ ] Version 1.01 let an SDSC card use a 4-bit field to indicate 1,024 or 2,048 bytes per block instead. Doing so enabled cards with 2 GB and 4 GB capacity, such as the Transcend 4 GB SD card and the Memorette 4GB SD card. Early SDSC host devices that assume 512-byte blocks therefore do not fully support the insertion of 2 GB or 4 GB cards.

In some cases, the host device can read data that happens to reside in the first 1 GB of the card. If the assumption is made in the driver software, success may be version-dependent.

In addition, any host device might not support a 4 GB SDSC card, since the specification lets it assume that 2 GB is the maximum for these cards. [ ] Storage capacity calculations [ ] The format of the Card-Specific Data (CSD) register changed between version 1 (SDSC) and version 2.0 (which defines SDHC and SDXC). Dismantled microSD to SD adapter showing the passive connection from the microSD card slot on the bottom to the SD pins on the top Like most memory card formats, SD is covered by numerous and. Royalties for SD card licences are imposed for manufacture and sale of memory cards and host adapters (US$1,000/year plus membership at US$1,500/year), but cards can be made without royalties. Early versions of the SD specification were available only after agreeing to a (NDA) that prohibited development of an driver. However, the system was eventually, and free software drivers provided access to SD cards that did not use DRM. Since then, the SDA has provided a simplified version of the specification under a less restrictive license.

Although most open-source drivers were written before this, it has helped to solve compatibility issues. In 2006, the SDA released a simplified version of the specification of the host controller interface (as opposed to the specification of SD cards) and later also for the physical layer, ASSD extensions, SDIO, and SDIO Type-A, under a disclaimers agreement. Again, most of the information had already been discovered and had a fully free driver for it. Still, building a chip conforming to this specification caused the project to claim 'the first truly Open Source SD implementation, with no need to obtain an SDI license or sign NDAs to create SD drivers or applications.' The proprietary nature of the complete SD specification affects, laptop computers, and some desktop computers; many desktop computers do not have card slots, instead using -based if necessary. These card readers present a standard interface to memory cards, thus separating the operating system from the details of the underlying SD interface.

However, embedded systems (such as portable music players) usually gain direct access to SD cards and thus need complete programming information. Desktop card readers are themselves embedded systems; their manufacturers have usually paid the SDA for complete access to the SD specifications. Many notebook computers now include SD card readers not based on USB; device drivers for these essentially gain direct access to the SD card, as do embedded systems. The -bus interface mode is the only type that does not require a host license for accessing SD cards. Comparison to other flash memory formats [ ].

Size comparison of various flash cards: SD,,, Overall, SD is less open than. Those can be implemented without paying for licensing, royalties, or documentation. (CompactFlash and USB flash drives may require licensing fees for the use of the SDA's trademarked logos.) However, SD is much more open than, for which no public documentation nor any documented legacy implementation is available. All SD cards can be accessed freely using the well-documented bus. Cards are simply 18-pin chips in a special package and support for raw NAND flash access. Although the raw hardware interface to xD cards is well understood, the layout of its memory contents—necessary for interoperability with xD card readers and digital cameras—is totally undocumented.

The consortium that licenses xD cards has not released any technical information to the public.