Protocol Frame Description

Table 5-9 .System Set Sound Data 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

 

 

 

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 SYSTEM_POWER_DOWN command enables the Remote Controller to power down Command 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

 

 

Protocol

 

 

 

Frame Start

Channel

Command

Data Length

Data

CheckSum

 

 

 

 

 

 

7Eh

Not used,

06h

00h

No

Yes

FFh

 

 

 

 

 

 

 

 

 

 

 

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

AT83SND2MP3

Resistor

 

0 ohm

INTO / P3.2

 

RXD

TXD

AT83SND2CMP3 User Guide

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7525A–MP3–07/05