Atmel AT83SND2C MP3 - Manual (Page 13)

Communication Protocol
AT83SND2CMP3 User Guide 3-9
7525A–MP3–07/05
• Checksum (1 byte): Frame checksum: 8 least significant bit of the sum of: Channel
+ Protocol Command + Data Length + Data.
In the following discussion, the Channel parameter is set to FFh.
3.3 Remote Controller - AT83SND2CMP3 Command Set List
There are several command types:
„
System Command: these commands allow to configure the system.
„ Player Command: these commands allow to access all the Player’s functions.
„ File System Command: these commands allow to navigate in selected memory: file
and directory architecture for the Card Memory.
„ Streaming Memory Driver Interface Command: these commands allow the
Remote Controller to stream MP3 music upon Player’s requests.
„ Custom Command: these commands allow the Remote Controller to do specific
requests.
Table 3-1 . System Command
Protocol Command Command Data Description
SYSTEM_RESET 00h No Software reset the AT83SND2CMP3. There is no answer for this
command. Refer to Player Reset section.
SYSTEM_CONFIG 01h Yes Configure the player in a pre-defined state
SYSTEM_GET_STATUS 02h No Asks the Player Status byte
SYSTEM_AUDIO_OUTPUT 03h 1 Byte Select Player Audio Output:
•
Headset
• Headset and Power Amplifier
SYSTEM_SELECT_MEMORY 04h 1 Byte Select Memory on:
•
NandFlash (NF)AT83SND2CMP3
• Card (SD/ MMC) connected to AT83SND2CMP3
When FAT is mounted, FNA is set in Player’s status (refer to
Table 5-1) and SYSTEM_MOUNTED* frame is sent.
SYSTEM_SET_SOUND 05h 5 Bytes Set digital sound and digital equalization.
Refer to set sound command description
SYSTEM_POWER_DOWN 06h No Power Down the Player
SYSTEM_WAKEUP 07h No Wake-up the Player.
Warning: this command requires AT83SND2CMP3 RXD line
connected to INTO pin (P3.2) in hardware.
SYSTEM_USB_DETACH 08h No Ask the Player to perform an USB Mass Storage detach.
SYSTEM_USB_CONNECT 09h No Ask the Player to perform an USB Mass Storage PC Connection.
Reserved 0Ah No Reserved.
SYSTEM_VOLUME_UP 0Bh No Analog Gain control volume up
SYSTEM_VOLUME_DOWN 0Ch No Analog Gain control volume down