Ans) SD(Secure Digital) Card:-
It is a portable, non-volatile memory card that is used in various
devices like camera, mobile, etc for providing memory storage
solutions
File system structure of a standard SD
card:- File system Structure basically means
the way in which files are named and stored in a particular device
such that they are stored and retrieved logically without which the
files are no longer accessible and becomes isolated for lifetime
hence File system Structure is important part of a storage
device
For Standard SD card :-
- (BP 0 to 2) Jump Command
- (BP 3 to 10) Creating System Identifier
- (BP 11 and 12) Sector Size
- (BP 13) Sectors per Cluster
- (BP 14 and 15) Reserved Sector Count
- (BP 16) Number of FATs
- (BP 17 and 18) Number of Root-directory Entries
- (BP 19 and 20) Total Sectors
- (BP 21) Medium Identifier
- (BP 22 and 23) Sectors per FAT
- (BP 24 and 25) Sectors per Track
- (BP 26 and 27) Number of Sides
- (BP 28 and 29) Field reserved for future standardization
- (BP 30 to 509) Field reserved for system use
- (BP 510 and 511) Signature Word
- (Extended FDC Descriptor BP 28 to 31) Number of Hidden
Sectors
- (Extended FDC Descriptor BP 32 to 35) Total Sectors
- (Extended FDC Descriptor BP 36) Physical Disk Number
- (Extended FDC Descriptor BP 37) Reserved
- (Extended FDC Descriptor BP 38) Extended Boot record
Signature
- (Extended FDC Descriptor BP 39 to 42) Volume ID Number
- (Extended FDC Descriptor BP 43 to 53) Volume Label
- (Extended FDC Descriptor BP 54 to 61) File System Type
- (Extended FDC Descriptor BP 62 to 509) Field reserved for
system use
- (Extended FDC Descriptor BP 510 and 511) Signature Word
The File Allocation Table supports both the 12-bit FAT and the
16-bit FAT by above specified structure we can get idea of what an
standard SD card file system looks like in order to manage( store
and retrieve) data properly and following a logical schema