AN706-00040-2v0-E
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7.2.6.2 AAC
(1) The application operation flow with audio data playback stopped is as follows.
①
USB MSC device connection/disconnection judgment is executed in the main
loop.
②
If the USB memory is connected, switch press-down detection is executed.
③
If the play/stop switch is detected to have been pressed down, the AAC file
selected from the USB memory is opened. If the selection previous switch or
selection next switch are detected to have been pressed down, AAC selection is
shifted and LED control is executed.
④
The AAC file header is read, AA file header analysis processing is conducted and
operation shifts to audio data playback status.
This operation is shown in Figure 50.
music1.aac
music2.aac
music3.aac
music4.aac
music5.aac
Open selected AAC file
Read selected AAC header data
and execute AAC header
analysis processing
Select AAC, LED control
LED state
No
Yes
Yes
No
No
Yes
AAC
header
Media files
Switch detection module
Play/Stop
switch
Selection
previous
switch
Selection
next switch
Switch chattering
processing
Timer interrupt(ch.2)(1ms)
LED control driver module
LED1 LED2 LED3 LED4 LED5
USB-MSC device connection/
disconnection judgement
Was media connected?
Was the Play/Stop
switch pressed?
Switch press detection
Change to audio data
playback state
Switch
state
Was the
Selection
previous switch or
Selection next switch
pressed?
Figure 50 Application Operation Flow (Audio Playback Stopped Status, Case of AAC)
