BU94605AKV Datasheet, PDF (34/84 Pages) Rohm – AAC/WMA/MP3 +SD Memory Card +CD-ROM+MP3 Record

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Datasheet
14. File search
14.1 Function
⋅ The file search function supports file system of FAT32, FAT16 and FAT12. (NTFS is not supported.)
⋅ The number of maximum playable files per folder.
Table 15. Maximum Playable Files per Folder
FAT12
FAT16
FAT32
Root folder
512
512
65535
Sub folder
65534
65534
65534
The number of files described above includes folders and files other than playable files (WAV/AAC/WMA/MP3). Thus, if
non-playable files or folders contain in the above folders and the number of total files exceeds the maximum limit, all
the playable files may not be played.
⋅ Less than 100 files in the order of FAT within each folder are sorted according to UNICODE. More than 100 files, if
any, will be sorted in the FAT order. The same rule is applied when sorting sub-folders. More than 100 sub-folders, if
any, will be sorted in the FAT order. A sorting function can be selected valid or invalid with a command.
⋅ The folder hierarchies up to 16 hierarchies whose full path including the file name is within 260 characters can be
searched.
⋅ Supports the device size up to FAT specification (2T byte).
⋅ Supports 512, 1024, 2048 and 4096 bytes per sector.
14.2 Playable file
The playable file extension is *.WAV for the WAV file, *.M4A, *.3GP and *.MP4 for the AAC file, *.ASF and *.WMA for
the WMA file, and *.MP3, *.MP2 and *.MP1 for the MP3 file. (There is no distinction between upper case letters and
lower case letters.) Note that the file operation differs in the following cases
⋅ SET_MP3 : For details, see SET_MP3 command.
⋅ Attribute : Files with hidden attributes are also playable. Files with system attributes cannot be played.
⋅ File name : The file name, including its size, does not depend on playability.
⋅ File size : A file with file size "0" is not recognized as a playable file. Playable file size up to 2G-1 byte. A file over
2Gbyte is recognized as a playable file, too. But, it is for 2Gbyte -1byte that it can play.
14.3 File playing sequence
The file playing sequence depends on the following rules when sort function valid. See Figure 35.
[1] Files of 1 to 100, in the order written to FAT (FAT order) in each folder, are sorted in the order of UNICODE.
Files more than 100 are played in the FAT order. The same rule is applied when sorting sub-folders.
MP3 files are sorted for MP3 which conforms to SEL_MP3. All the folders including null ones and those to which
no playable file is written are sorted. If over 100 playable files or sub-folders are contained in the folder, they are
played in the order written to the FAT directory entries.
The writing method of directory entries will not help understand the file play order because the method depends
on the OS operation at writing.
[2] When a playable file exists in the root folder (the top hierarchy), the file is to be played first.
[3] After all the playable files within the root folder have been played, playable files in the folder in the lower hierarchy,
if any, are played.
[4] If another folder exists in the lower hierarchy, playable files within this folder are played. If not, the LSI searches
other folders in the same hierarchy. If another folder exists there, the LSI plays that folder.
[5] After playing all the files, the LSI returns to the root folder as in [2] and play the files starting with the top sorted
one.
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2012.12.10 Rev.002