Atmel AT83SND2C MP3 - Manual (Page 35)

Protocol Frame Description
AT83SND2CMP3 User Guide 5-31
7525A–MP3–07/05
Table 5-9 . System Set Sound Data Command
Note: All value set to FFh will not be updated in Player. Example: MP3VOL set to FFh means
tMP3VOL will keep its last value.
SYSTEM_POWER_DOWN
Command
SYSTEM_POWER_DOWN command enables the Remote Controller to power down
AT83SND2CMP3 system. The Audio capacitors are discharged before entering the
power down mode. The AT83SND2CMP3 is placed then in a very low power state. To
wake it up, refer to SYSTEM_WAKEUP command.
Table 5-10 . SYSTEM_POWER_DOWN Command Format
Note: To avoid audio capacitors discharge in power down mode, refer to command
CUSTOM_SYSTEM_SLEEP (power down with audio capacitors charged).
SYSTEM_WAKEUP Command SYSTEM_WAKEUP Command is a special command: it is 1ms (at least) of logical level
“0” on AT83SND2CMP3 GPIO INT0.
In the case that Remote Controller Tx is connected to AT83SND2CMP3 INTO, it is
possible to change the Remote Controller UART baudrate to 9600bps and send the byte
00h.
AT83SND2CMP3 UART is not active in Power down mode.
Note: INTO (P3.2) pin is an external interrupt that enable the AT8xC51SND2C to wake up if a
low level is applied on it.
Figure 5-1 . AT83SND2CMP3 Configuration for SYSTEM_WAKEUP Command
Byte Number Byte Mnemonic Description
0 MP3VOL MP3 Volume Left Channel
1 MP3VOR MP3 Volume Right Channel
2 MP3BASS MP3 Bass equalization
3 MP3MED MP3 Medium equalization
4 MP3TRE MP3 Treble equalization
Frame Start Channel
Protocol
Command Data Length Data CheckSum
7Eh
Not used,
FFh
06h 00h No Yes
AT83SND2MP3
RXD
TXD
INTO / P3.2
0 ohm
Resistor