Specifications

5.3.6 Playing MP3 data
To play the MP3 data that is stored in the buffer through the MP3 decoder, the transfer
needs to be at one byte at a time. The data transfer function provided with the Nut OS
was modified to take data from the buffer that was created. The following is a flow
chart of how this function works.
Data
request ISR
Return
Is the
transfer
enabled
Select the
decoder data
register
Buf f er
emtpy
Decoder
full
Send data to
the decoder
Increment
transmit
pointer
Reset pointer if
it is past the end
of the buffer
Return
Return
Send 32 more
bytes to the
decoder
No
Yes
Yes
No
Yes
No
Figure 17 Interrupt service routine to transfer data to the decoder
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