The SD memory cards known as the “Secure Digital” first began as miniature cards. Afterwards the new and advanced form of the SD memory card SDIO “Secure Digital Input/output” was introduced into the market. The SDA “Secure Digital Association” included new features and technology to the SD memory cards. The SDA included new varieties of card functions. These new card functions included wireless “Local Area Network LAN” devices, cell phones, GPS receiver, digital video camera etc. The memory card readers that were used in the Secure Digital devices connected to the Universal Serial Bus (USB). The Windows Operating System detects and manages the SD (Secure Digital) memory cards through the driver called the (USB) Universal Serial Bus mass storage. The (SD) Secure Digital host controllers are supported by the Operating System. The Operating System connects the host controller SD to the Peripheral Component Interconnect (PCI) bus. When the SD-host controller is detected by the operating system, the “SD Secure Digital bus driver” is loaded by the operating system OS. When the SD card is inserted by the user, the windows Operating system loads two drivers the “Storage mini-port” and the “SD Secure Digital Storage Class”. These two drivers are loaded on top of “Bus driver” by the Windows Operating System. On the other hand if the SD memory card of a different function like the wireless Local Area Network (LAN) or the Global Positioning System is inserted by the user, then the Windows Operating System loads the driver that is supplied by the vendor. It is necessary that both the vendor supplied and the native drivers in the (SD) Secure Digital stack communicate with “Secure Digital Bus”. The device drivers call the routines to communication with the “Secure Digital Bus”. These routines are called in the static “Secure Digital Bus library”. When the SD Secure Digital drivers compile, it is necessary that they link to the “Secure Digital SD Bus library”. There are some limitations for the SD device drivers. The “Host Controller Register” is not directly accessible by the Secure Digital device drivers.
The SD device drivers call the routines of “Secure Digital Library”. Then the Secure Digital Library forwards the Secure Digital commands to “Host Controller”. Music can be stored in the Flash Memory card and it is most advantageous than storing it in the Hard drives. The SD flash memory cards consume less power and are more portable. The SD flash cards also have resistance to shocks. The SD card facilities its users and they can easily record the data to their personal liking like music, pictures. The users can easily carry and move the data with ease and comfort. The SD memory card has the technology to fulfill the requirements of the future networked society. The tiny SD memory card provides many advantages to their users. These memory cards are highly compatible and they can link to different digital equipments. Because of the compatibility of the SD memory cards, their usage is more likely to expand even more in the future. The SD card has now become a standard of memory cards that are used for digital connectivity. In the near by future, the SD cards will be universally accessible to more wide array of Multimedia data. The size of the SD memory card is approximately 24mm x 32mm x 2.1mm. The design of the SD card is very compact and slim. Therefore, they are easy to handle and the user can easily transfer the data.
The devices that are compatible with SD card can play video clips & music with the help of “decoder software”. The DVD & CD players use “drive mechanism” while the SD memory cards do not require “drive mechanism” to play the video clips. So, this gives the product designers more freedom and they can be more creative and innovative. The other popular form of the SD memory card is the miniSD memory card. The size of the mini-SD card is approximately 20mm x 21.5mm x 1.4mm. The miniSD card is smaller in size than the SD card.
The SD memory cards have different recording capacitates, their capacity reaches up to 8GB. The large capacity helps to store the High quality videos. The demand for high capacity SD cards with fast data transfer speed has increased because of the increased digital content range. The SD cards also have the technology of “Copyright Protection”. This “Copyright Protection” technology enables new distribution system. This provides safety and security to the illegal copying of the data.The SD card has built in technology called the Key Revocation. The SD memory card has “Control Circuit”, which allows to read & write the after the detection of the external devices. The data is written and read within the “protection area” of the card. The authentication among the digital devices has to be enabled so that the SD card could be accessed.
