Atmel AT83SND2C MP3 - Manual (Page 45)

Protocol Frame Description
AT83SND2CMP3 User Guide 5-41
7525A–MP3–07/05
Table 5-41 . FS_GET_NAME command
Note: When selected root or directory is empty, the returned file name is ‘\0’.
FS_FORMAT Command Format Selected Memory in FAT16. Player reponse is SYSTEM_ACK* or
SYSTEM_NACK* frame.
It is necessary to send the SYSTEM_ SELECT_MEMORY once (to select the memory)
before sending the FS_FORMAT command.
Player status can be viewed in Status Byte (Memory Error or File Name Available).
Table 5-42 . FS_FORMAT command
Note: Depending of the memory type and size, Player response can be up to several seconds.
NandFlash 64 Mo: ~6 seconds, SD card: ~4 seconds.
FS_FCREATE Command Create a File in root dir in Selected Memory. Once this file is created, Player is waiting
for ‘Number of Blocks’ FS_FWRITE_BLOCK commands.
Table 5-43 . FS_FCREATE command
„ Block size: Depending of transfer link, size of a block can change. For the UART link,
block size is always equal to sector size 512 bytes. Block size is not a parameter in
FS_FCREATE command.
„ Number of Blocks Parameter: this is File length in Block. For a 2384 Bytes File, it is
necessary to transfer 5* FS_WRITE_BLOCK commands (Number of Blocks = 5)
with stuffing bytes in last command FS_WRITE_BLOCK.
„ The File_Name is a ASCII long filename with extension already formatted:
“song1.mp3”. Example: File_name ‘S’,’O’,’N’,’G’,’1’ , ‘.’ , ’M’, ‘P’, ‘3’ ‘\0’. File name
length is limited to 8 characters. Extension is limited to 3 characters.
To create a File:
– FS_CREATE (Number of blocks, File name),
– (Number of blocks-1) x FS_WRITE_BLOCK (512 bytes data),
– FS_WRITE_LAST_BLOCK (Number of bytes < 512), Player response is then
SYSTEM_ACK. File is created.
Frame Start Channel
Protocol
Command Data Length Data CheckSum
7Eh
If not used,
FFh
64h 00h No Yes
Frame Start Channel
Protocol
Command Data Length Data CheckSum
7Eh
If not used,
FFh
65h 00h No Yes
Frame Start Channel
Protocol
Command Data Length Data CheckSum
7Eh
If not used,
FFh
66h Nh
Byte 0 MSB(Number of blocks)
Byte 1 LSB(Number of blocks)
Byte 2:N-1 File Name (must
finish with ‘\0’).
Yes