User Manual
Table Of Contents
- Revision History
- Table of Contents
- Target products
- 1 INTRODUCTION
- 2 OVERVIEW OF SIMPLE AV SYSTEM BOARD
- 3 PREPARATIONS
- 4 PROGRAM EXECUTION METHOD
- 5 SUPPORTED MEDIA
- 6 OPERATION METHOD
- 7 SPECIFICATIONS
- 7.1 Hardware
- 7.2 Software
- 7.2.1 Software Block Diagram
- 7.2.2 Software Library
- 7.2.3 System Specifications
- 7.2.4 API Specifications
- 7.2.5 Operation Limit
- 7.2.6 Operation Flow of Entire Application
- 7.2.7 Application State Transition
- 7.2.8 Operation Flow
- 7.2.8.1 Main Processing Function
- 7.2.8.2 USB Task Processing Function
- 7.2.8.3 File System (MDF) Task Processing Function
- 7.2.8.4 HMI Task Processing Function
- 7.2.8.5 AUDIO Play Task Processing Function
- 7.2.8.6 Switch Press Detection Processing Function
- 7.2.8.7 Processing Function After Switch Press Detection
- 7.2.8.8 Touch Panel Touch Detection Processing Function
- 7.2.8.9 Processing After Touch Panel Touch Detection Function
- 7.2.9 File Configuration
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(2) The application operation flow with audio data playback in progress is as follows.
① USB MSC device connection/disconnection judgment is executed in the main
loop.
② If the USB memory has been removed, stop playback, close the opened AAC file,
quit the file system and operation shifts to initialization status.
③ If the USB memory is connected, play/stop button press-down detection is
executed.
④ If the play/stop button is detected to have been pressed down, playback stops,
the AAC file is closed, and operation shifts to audio data playback stop status.
⑤ Verify vacancy of input buffer.
⑥ If there is sufficient vacancy, the AAC file is read from the USB memory and
copied in the input buffer.
⑦ One elementary stream of the input buffer is decoded and stored in the RAW
buffer.
⑧ When 1 elementary stream had been decoded, the RAW buffer is up-sampled
and buried in the output buffer.
⑨ With DMA ch2 interrupt, data is sent from the output buffer to I
2
S in sequence.
This operation is shown in Figure 51.