Protocol Frame Description

Table 5-41 .FS_GET_NAME command

 

 

Protocol

 

 

 

Frame Start

Channel

Command

Data Length

Data

CheckSum

 

 

 

 

 

 

7Eh

If not used,

64h

00h

No

Yes

FFh

 

 

 

 

 

 

 

 

 

 

 

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

 

 

Protocol

 

 

 

Frame Start

Channel

Command

Data Length

Data

CheckSum

 

 

 

 

 

 

7Eh

If not used,

65h

00h

No

Yes

FFh

 

 

 

 

 

 

 

 

 

 

 

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

 

 

Protocol

 

 

 

 

Frame Start

Channel

Command

Data Length

 

Data

CheckSum

 

 

 

 

 

 

 

 

 

 

 

Byte 0

MSB(Number of blocks)

 

7Eh

If not used,

66h

Nh

Byte 1

LSB(Number of blocks)

Yes

FFh

Byte 2:N-1 File Name (must

 

 

 

 

 

 

 

 

finish with ‘\0’).

 

 

 

 

 

 

 

 

„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.

AT83SND2CMP3 User Guide

5-41

7525A–MP3–07/05