Most recently, recording media in appliances with auxiliary memory units of digital information, such as digital cameras, have advanced to memory cards (or IC cards), such as smart media cards, multimedia memory cards, and so forth. In years past, optical disks, magnetic disks (e.g., floppy disks and hard disks), computer disks (CD) and digital video disks (DVD) have been the state of the art. Recently, memory cards based on flash memories recently developed have been a center attraction due to their small size, convenience and fast transmission speed. A typical example is an extreme digital picture card (hereinafter inclusively referred to as “xD card”), which was developed as a memory card for a digital camera.
An xD card is a kind of memory card that uses NAND flash memories, and is also the next generation flash memory card in order to satisfy disadvantages of conventional smart media cards such as limitations of size and capacity.
An xD card is connected to a host (e.g., digital cameras) through a direct connection system. Accordingly, these xD cards, compared with conventional flash cards, secure digital (SD) cards, memory sticks, multimedia memory cards and so forth, have many advantages in the fact that they have a large data storage capacity with small size (25×20×1.7(mm)), fast transmission speed, and small power consumption.
xD cards may be classified into a small xD card using a small capacity NAND flash memory having a 16 Kilo Byte (hereinafter inclusively referred to as “KB”) block size and a large xD card using a large capacity NAND flash memory having a 128 KB block size. However, there is a problem in that the large and small capacity NAND flash memories, which are used as memories of xD cards, uses different interface modes, respectively.
Therefore, the large capacity xD card is not directly available to a host for supporting the small capacity xD card. Conversely, the small capacity xD card is not directly available to a host for supporting the large capacity xD card. These problems are not necessarily confined to xD cards, but are common problems in the field of memory cards based on flash memories.