Fujitsu FM3 family User Manual page 72

USB-MSC device connection/
disconnection judgement
Was media disconnected?
Stop AAC play
Close AAC file
End file system
Change to initialization state
Swith press detection
Was the Play/Stop
switch pressed?
Stop AAC play
Close MP3 file
Media files
Change to audio data
playback stop state
music1.aac
music2.aac
music3.aac
music4.aac
music5.aac
Figure 51 Application Operation Flow (Audio Playback Status, Case of AAC)
No
Switch detection module
Yes
No
Yes
No
No
Timer interrupt(ch.2)(1ms)
Switch chattering
Selection
Play/Stop
previous
switch
switch
Switch
state
Are there enough empty
area in the input buffer?
Yes
Read AAC data from media
and copy in the input buffer
One frame of the data in the
input buffer is decoded, then
store it to the RAW buffer
Was one frame
decoded successful?
Yes
Up-sample the RAW buffer data
and copy it to the output buffer
71
AN706-00040-2v0-E
processing
Selection
next switch
DMA interrupt(ch.2)
Sampling data
output module
PCM
data
I 2 S
output
Output
buffer
PCM
data