What kinds of storage formats do cameras have?

Memory card type: Flash card is a memory that uses flash technology to store electronic information. Generally, it is used as a storage medium in digital cameras, palmtop computers, MP3 and other small digital products, so it looks like a card, so it is called a flash card. According to different manufacturers and different applications, flash cards probably include SmartMedia(SM card), Compact Flash(CF card), MultiMediaCard(MMC card), Secure Digital(SD card), Memory Stick (memory stick), XD-Picture card (XD card) and MICRODRIVE. Although the appearance and specifications are different, the technology is the same. Memory cards used as mobile phones include MMC card, RS-MMC card, SD card, mini SD card, T-Flash card, Sony memory stick and CF card. Access speed: Access speed refers to the data transmission speed of flash memory card when writing or reading data. Different types of flash memory cards adopt different interface specifications, and naturally their access speeds are also different. Even the same type of memory cards will be interfered by the manufacturing level of various manufacturers, the quality of card readers and even the performance of connecting the host, which actually shows different access speeds. When the same card is applied to different cameras, it may also show a difference in speed, which is affected by the performance difference of the camera flash card interface. The access speed of flash memory cards claimed by various manufacturers is basically the highest access speed of flash memory cards in a certain state, which can hardly be achieved in practical application. The concept of dual-speed flash memory card is also widely circulated in the market, such as 40 times speed CF card. Double speed is the speed calculation concept of optical storage equipment. If 1 double speed is equal to 150KB/s data transmission speed, then 40 times speed will reach 6MB per second. But in practical application, these high-speed flash cards can't reach such a high speed, and may reach or approach such a high speed on a specific digital camera or card reader device. But in most applications, high-speed flash cards are indeed faster than ordinary flash cards, but they are not so many times faster than ordinary flash cards. Voltage: Different types of flash memory cards have different specifications and different normal working voltages. However, different flash card interfaces are different, so there is no possibility of inserting the wrong interface. Therefore, the flash memory card will not be damaged because of the wrong interface and different working voltages. The data transmission and physical specifications of SD card are all developed from MMC, and the size is similar to MMC. The SD card and MMC card remain upward compatible, that is, new SD devices can access MMC, and the compatibility depends on the application software, but the SD card cannot be accessed by MMC devices. Even so, it is recommended that what type of flash card corresponds to what type of interface to avoid unnecessary mistakes. MMC card: MMC (Multimedia Card) card was introduced by Siemens and SanDisk, who started CF, in 1997. 1998 65438+ 10 Fourteen companies jointly established the MMC Association (MMCA), with more than 84 members at present. The development goal of MMC is mainly aimed at digital images, music, mobile phones, PDA, e-books, toys and other products. It is claimed to be the smallest flash memory card in the world at present, with a size of only 32 32 mm x 24 mm x1.4 mm. Although it is thicker than SmartMedia, its overall size is smaller and lighter than SmartMedia. Only1.5g ... MMC also puts the storage unit and controller on the card, and the intelligent controller ensures the compatibility and flexibility of MMC. MMC memory cards can be divided into two working modes: MMC and SPI. MMC mode is the standard default mode and has all the characteristics of MMC. SPI mode is the second mode of MMC memory card and a subset of MMC protocol, which is mainly used in systems that only need a few cards (usually 1) and have low data transmission rate (compared with MMC protocol). This mode can minimize the design cost, but the performance is not as good as MMC. MMC is designed as a low-cost data platform and communication medium, and the interface design is very simple: only 7 pins! The interface cost is less than $0.50, in contrast, the interface cost of SmartMedia and memory stick is higher than $65,438 +0. On the interface, the power supply is 3-pin, and data operation only needs 3-pin serial bus (SPI mode plus 1 pin chip selection). The working voltage of MMC is 2.7 volts to 3.6 volts, and the write/read current is only 27mA and 23mA, so the power consumption is very low. Its reading and writing methods include streaming, multi-block and single block. The minimum data transmission is in blocks, and the default block size is 5 12 bytes. Representative models: Nokia N-Gage QD, 77 10, 6600, 3650, etc. RS-MMC card: full name (multimedia card with reduced size). The card standard was first issued by MMCA (Multimedia Card Association) in June 2002. Its size is only half that of the standard MMC card, but it inherits all the advantages and performance characteristics of the latter. Through the adapter card, it is also suitable for the original MMC and SD interface devices supporting MMC. Representative models: Samsung D7 10, 730, V500, SPH-V4400, Nokia 6260, 6630, 6670, 76 10, Siemens S65, Panasonic X700, etc. SD card: SD card (Secure Digital Memory Card) is a new generation storage device based on semiconductor flash memory. The SD card was jointly developed by Panasonic, Toshiba and SanDisk Company of the United States in August 1999. The stamp-sized SD memory card weighs only 2 grams, but it has high storage capacity, fast data transmission speed, great mobility and good security. In the volume of 24mm×32mm×2. 1mm, the SD card combines SanDisk flash memory card control with MLC (multi-level unit) technology and Toshiba's NAND technologies 0. 16u and 0. 13u, and is connected with a special driver through a 9-pin interface, so there is no need for additional power supply to keep the information stored on it. Moreover, it is an integrated solid medium without any moving parts, so there is no need to worry about the damage of mechanical movement. The data transmission and physical specifications of SD card are developed from MMC, and the size is similar to MMC, with the size of 32 mm x 24 mm x 2. 1 mm ... The length and width are the same as MMC, but the thickness is increased by 0.7 mm to adapt to larger storage units. The SD card and MMC card remain upward compatible, that is, new SD devices can access MMC, and the compatibility depends on the application software, but the SD card cannot be accessed by MMC devices. (The shape of SD card adopts the track design with the same thickness as MMC, so that SD equipment can be applied to MMC. In addition to retaining 7 pins of MMC, SD interface also adds 2 pins on both sides as data lines. NAND flash memory is adopted, which is basically the same as SmartMedia's, and the average data transmission rate can reach 2MB/s. The structure of SD card can ensure the security of digital file transmission, and it is also easy to reformat, so it has a wide range of applications, and multimedia files such as music, movies and news can be conveniently stored in SD card. So many digital cameras have started to support SD cards. Many memory card companies have developed SD cards. Panasonic is the main manufacturer of SD cards at present. In 2000, the capacity of SD card was divided into four different grades from 8MB to 64MB to meet the needs of different occasions. The data transmission rate was 2 MB/s. By the end of 5438+0 in 2006, the capacity of a single card had reached 5 12MB, and the data transmission rate was also increased to10 MB/s. In 2003, the capacity was. Representative models of data transmission rate: dopod 515,535, 8 18, Shenda MIO8390, LGG9 10, Lenovo ET960, etc. Mini SD card: full name (mini secure digital memory card). MiniSD card is developed from SD card, and its performance is not much different from that of traditional SD card. MiniSD card, like SD card, has a data transmission speed of 2MB per second. Like the traditional SD card, the miniSD card also has a hardware data write protection switch, which can avoid the risk of accidentally deleting the stored content. MiniSD card is characterized by its small size (the size is only 2 1.5×20x 1.4mm, which is 40% smaller than the original SD card), stable performance, which can be used with special adapter cards and fully compatible with standard SD card slots. Moreover, the miniSD card is designed with low power consumption, which is more suitable for mobile communication devices than the SD card, so it mainly attacks mobile phones, PDA and PDA information terminals. Representative models: dopod 565, 575, moto MPX220, etc. T-Flash card: TransFLash was developed by Motorola and SANDISK*** and launched in 2004. It is a very small card (11*15 *1mm). TF card can be used as SD card after SD card converter. Supported models: Motorola A780, E398, C975, etc. Sony memory stick: memory stick, developed by Sony, with a size of 50mm x 2 1.5mm x 2.8mm and a weight of 4 grams. It uses a delicate and striking blue case (the new MG is white) and has a write protection switch. Unlike many flash memory cards, the specifications of memory sticks are not open and there is no standardization organization. Adopt Sony's own appearance, protocol, physical format and copyright protection technology. To use its specifications, it is necessary to negotiate and sign a license with Sony. The memory stick also includes a controller, a 10 pin interface and a serial data bus. The maximum frequency is 20MHz, the voltage is 2.7V to 3.6V, and the average current is 45mA. It can be seen that this specification is quite similar to MMC that appeared at about the same time. Sony emphasizes that its interface with independent needle slot is easy to insert or pull out of the slot and is not easy to be damaged; But also never contact with each other, thus greatly reducing the error caused by needle contact and making data transmission more reliable; It is also easier to clean than a pin memory card. The advantages of memory stick include compact appearance, high stability, copyright protection function and convenient use in various memory stick series products, as well as a large number of products introduced by Sony that make use of this technology, such as DV cameras, digital cameras, VAIO personal computers, color printers, walkman, IC tape recorders, LCD TVs and so on. , as well as PC card converter, 3.5-inch floppy disk converter, parallel export converter, USB reader and other full range of accessories, so that the memory stick can easily connect PC and MAC. After the introduction of memory stick, a series of companies such as Samsung, Aihua, Sanyo, Casio, Fujitsu, Olympus and Sharp all expressed their support for this format. Sony is still seeking the recognition of memory chip format in the home appliance industry and IT industry. Sony will introduce more products representing the latest development of memory sticks to the domestic market in the future. The disadvantage of memory stick is that it can only be used on Sony digital camera, and its capacity is not large enough. Support Sony Ericsson P908, P9 10C, S700C, etc. CF card: Compact flash memory was first introduced by SanDisk in 1994. CF card has PCMCIA-ATA function and is compatible with it; The weight of CF card is only 14g, which is only the size of a cardboard match (43mm x 36m x m3.3mm). It is a solid product, that is, it works without moving parts. CF card adopts flash technology, which is a stable storage solution and does not need batteries to maintain the data stored in it. For the stored data, CF card is safer and more protective than the traditional disk drive. The reliability is 5 to 10 times higher than that of traditional disk drives and type III PC cards, and the power consumption of CF cards is only 5% of that of small disk drives. These excellent conditions make most digital cameras choose CF card as the preferred storage medium. Although CF card was originally a flash card, with the development of CF card, non-flash cards with various CF card specifications began to appear, and CFA later developed CF+ specification, which extended the scope of CF card to other fields of non-flash cards, including other I/O devices and disk storage. And a Type II specification with updated physical specifications (IBM's Microdrive is the CF card of Type II). The difference between Type II and the original Type I is that Type II is 5mm thick. CF card supports 3.3 volts and 5 volts at the same time, and any CF card can work under these two voltages, which makes it widely used. The compatibility of CF memory card also lies in that it combines the flash memory module with the controller, which can make the external devices using CF cards simpler, and can read and write different CF cards through a single mechanism without worrying about compatibility problems, especially when upgrading CF cards, which can ensure the compatibility of old devices. CF card has quite a lot of platform support, including DOS, Windows 3.x, Windows 95, Windows 98, Windows CE, OS/2, Apple System 7, Linux and many UNIX. As a worldwide storage industry standard, CF card ensures the compatibility of CF products and the backward compatibility of CF cards. With the more and more extensive application of CF card, manufacturers actively improve the technology of CF card and promote the launch of a new generation of advanced mobile devices with small size, light weight and low energy consumption, thus improving work efficiency. CFA is headquartered in Palo Alto, Canada, and members have the right to obtain CF cards, CF trademarks and CF technical details free of charge. CFA has more than 65,438+020 members, including 3COM, Canon, Kodak, Hewlett-Packard, Hitachi, IBM, Panasonic, Motorola, NEC, SanDisk, Seiko (Epson) and Socket Communications. Moreover, major digital camera manufacturers have set up special institutions to develop CF products. At present, the capacity of the world's largest CF card has reached 640M. Generally, there are 8MB, 16MB, 32MB, 64MB, 128MB, 256MB, etc. (1more than 28mb is type Ⅱ). Representative models: dopod 696, etc. Answer: February 26th, 2008 2 1: 32 Questioner's evaluation of the answer: **0 comments. ...