SPMA084 December   2021 TM4C1230C3PM , TM4C1230C3PM , TM4C1230D5PM , TM4C1230D5PM , TM4C1230E6PM , TM4C1230E6PM , TM4C1230H6PM , TM4C1230H6PM , TM4C1231C3PM , TM4C1231C3PM , TM4C1231D5PM , TM4C1231D5PM , TM4C1231D5PZ , TM4C1231D5PZ , TM4C1231E6PM , TM4C1231E6PM , TM4C1231E6PZ , TM4C1231E6PZ , TM4C1231H6PGE , TM4C1231H6PGE , TM4C1231H6PM , TM4C1231H6PM , TM4C1231H6PZ , TM4C1231H6PZ , TM4C1232C3PM , TM4C1232C3PM , TM4C1232D5PM , TM4C1232D5PM , TM4C1232E6PM , TM4C1232E6PM , TM4C1232H6PM , TM4C1232H6PM , TM4C1233C3PM , TM4C1233C3PM , TM4C1233D5PM , TM4C1233D5PM , TM4C1233D5PZ , TM4C1233D5PZ , TM4C1233E6PM , TM4C1233E6PM , TM4C1233E6PZ , TM4C1233E6PZ , TM4C1233H6PGE , TM4C1233H6PGE , TM4C1233H6PM , TM4C1233H6PM , TM4C1233H6PZ , TM4C1233H6PZ , TM4C1236D5PM , TM4C1236D5PM , TM4C1236E6PM , TM4C1236E6PM , TM4C1236H6PM , TM4C1236H6PM , TM4C1237D5PM , TM4C1237D5PM , TM4C1237D5PZ , TM4C1237D5PZ , TM4C1237E6PM , TM4C1237E6PM , TM4C1237E6PZ , TM4C1237E6PZ , TM4C1237H6PGE , TM4C1237H6PGE , TM4C1237H6PM , TM4C1237H6PM , TM4C1237H6PZ , TM4C1237H6PZ , TM4C123AE6PM , TM4C123AE6PM , TM4C123AH6PM , TM4C123AH6PM , TM4C123BE6PM , TM4C123BE6PM , TM4C123BE6PZ , TM4C123BE6PZ , TM4C123BH6PGE , TM4C123BH6PGE , TM4C123BH6PM , TM4C123BH6PM , TM4C123BH6PZ , TM4C123BH6PZ , TM4C123FE6PM , TM4C123FE6PM , TM4C123FH6PM , TM4C123FH6PM , TM4C123GE6PM , TM4C123GE6PM , TM4C123GE6PZ , TM4C123GE6PZ , TM4C123GH6PGE , TM4C123GH6PGE , TM4C123GH6PM , TM4C123GH6PM , TM4C123GH6PZ , TM4C123GH6PZ , TM4C1290NCPDT , TM4C1290NCPDT , TM4C1290NCZAD , TM4C1290NCZAD , TM4C1292NCPDT , TM4C1292NCPDT , TM4C1292NCZAD , TM4C1292NCZAD , TM4C1294KCPDT , TM4C1294KCPDT , TM4C1294NCPDT , TM4C1294NCPDT , TM4C1294NCZAD , TM4C1294NCZAD , TM4C1297NCZAD , TM4C1297NCZAD , TM4C1299KCZAD , TM4C1299KCZAD , TM4C1299NCZAD , TM4C1299NCZAD , TM4C129CNCPDT , TM4C129CNCPDT , TM4C129CNCZAD , TM4C129CNCZAD , TM4C129DNCPDT , TM4C129DNCPDT , TM4C129DNCZAD , TM4C129DNCZAD , TM4C129EKCPDT , TM4C129EKCPDT , TM4C129ENCPDT , TM4C129ENCPDT , TM4C129ENCZAD , TM4C129ENCZAD , TM4C129LNCZAD , TM4C129LNCZAD , TM4C129XKCZAD , TM4C129XKCZAD , TM4C129XNCZAD , TM4C129XNCZAD

 

  1.   Trademarks
  2. 1Introduction
  3. 2Pulse Width Modulation (PWM) emulation of a DAC
  4. 3Audio Sampling Rate and Resolution Analysis
    1. 3.1 Using the PWM DAC Method
    2. 3.2 Using Off-Chip DAC
  5. 4Audio File Data Format
    1. 4.1 WAV File Size Calculation
    2. 4.2 Storing WAV Audio on Internal Flash
  6. 5Hardware Setup
    1. 5.1 BOOSTXL-AUDIO BoosterPack Overview
    2. 5.2 Hardware Setup for EK-TM4C1294XL
    3. 5.3 Hardware Setup for EK-TM4C123GXL
    4. 5.4 Hardware Setup for DK-TM4C129x Development Board
  7. 6Application Examples
    1. 6.1 Examples: audio_playback_internal_wavefile_by_PWM_EKTM4C129 and audio_playback_internal_wavefile_by_SPIDAC_EKTM4C129
    2. 6.2 Examples: audio_playback_internal_wavefile_by_PWM_EKTM4C123 and audio_playback_internal_wavefile_by_SPIDAC_EKTM4C123
    3. 6.3 Examples: audio_playback_internal_wavefile_by_PWM and audio_playback_internal_wavefile_by_SPIDAC
    4. 6.4 Examples: audio_playback_with_sdcard_by_PWM and audio_playback_with_sdcard_by_SPIDAC
  8. 7Download and Import the Examples
  9. 8References

4 Audio File Data Format

There are many types of audio files. Common file formats used for storing audio data are MP3, WMA, FLAC, AAC and so forth. Audio files basically fall into three major categories – audio formats with lossy compression, audio formats with lossless compression and uncompressed audio formats.

A good representation of audio formats with lossy compression is MP3. MPEG-1 Audio Layer 3 (MP3) is the most popular audio format with compression. For lossless compression, Free Lossless Audio Codec (FLAC) has become one of the most popular lossless formats. Waveform Audio File Format (WAV) is an uncompressed audio format that captures and converts real sound waves to digital format without any further processing.

It is beyond the scope of this application note to go through the compression technologies and the pros and cons of different audio formats. For simplicity to demonstrate playing audio using DAC, the examples provided in this application report only use WAV format, which is an uncompressed audio format.