VS1033d Compared to VS1033c

The VS1033d datasheet version changes chapter lists the major differences. The following lists the most important ones.

Replacing VS1033c with VS1033d depends on what features you are using. If you use loadable code such as plugins, patches, or full-blown applications, you need to update them. If you use the chip in the simplest form by just sending data and controlling the SCI registers, the chip upgrade may be possible without changes to software.

The most important new features of VS1033d are:

• Layers I, II, and III : new, more robust and accurate decoding.
• mp3fix needed to correct a problem with the new mp3 decoding.
• MP3 is now full accuracy compliant. Use 3.0x clock to decode all MP3 bitrates and samplerates with bass and treble controls active.
• Seek length info no longer needed for resync (fast forward and rewind).
• Parametric_x.resync is set to zero by default. Set it to 32767 to enable infinite resyncs.
• New SCI_STATUS bit SS_DO_NOT_JUMP is set to 1 during header decode for WAV, ADIF, MP4, and WMA. Is always set for midi.
  Use it to see when fast forward/rewind is not allowed.
• All codecs support fast play mode and average bitrate calculation.
• Better WAV parser skips unknown RIFF chunks. Now WAV also handles mulaw decoding.
• WMA and AAC have more robust resync. If resync is performed, broadcast mode is automatically activated, so there's no need to fix the file size.
• If you use IMA ADPCM, the datasheet tells how to activate the ADPCM mode to avoid an issue in record monitoring.