Datasheet

VS1053b Datasheet
12 VERSION CHANGES
12 Version Changes
This chapter describes the lastest and most important changes done to VS1053b
12.1 Changes Between VS1033c and VS1053a/b Firmware, 2007-03-08
Completely new or major changes:
• I2S pins are now in GPIO4-GPIO7 and do not overlap with SPI boot pins.
• No software reset required between files when used correctly.
• Ogg Vorbis decoding added. Non-fatal ogg or vorbis decode errors cause automatic
resync. This allows easy rewind and fast forward. Decoding ends if the "last frame" flag
is reached or SM_CANCEL is set.
• HE-AAC v2 Level 3 decoding added. It is possible to disable PS and SBR processing and
control the upsampling modes through parametric_x.control1.
• Like the WMA decoder, the AAC decoder uses the clock adder (see SCI_CLOCKF) if it
needs more clock to decode the file. HE-AAC features are dropped one by one, if the file
can not be decoded correctly even with the highest allowed clock. Parametric stereo is
the first feature to be dropped, then downsampled mode is used, and as the final resort
Spectral Band Replication is disabled. Features are automatically restored for the next
file.
• Completely new volume control with zero-cross detection prevents pops when volume is
changed.
• Audio FIFO underrun detection (with slow fade to zero) instead of looping the audio buffer
content.
• Average bitrate calculation (byteRate) for all codecs.
• All codecs support fast play mode with selectable speeds for the best-quality fast forward
operation. Fast play also advances DECODE_TIME faster.
• WMA and Ogg Vorbis provide an absolute decode position in milliseconds.
• When SM_CANCEL is detected, the firmware also discards the stream buffer contents.
• Bit SCIST_DO_NOT_JUMP in SCI_STATUS is ’1’ when jumps in the file should not be
done: during header processing and with Midi files.
• IMA ADPCM encode now supports stereo encoding and selectable samplerate.
Other changes or additions:
• Delayed volume and bass/treble control calculation reduces the time the corresponding
SCI operations take. This delayed handling and the new volume control hardware pre-
vents audio samples from being missed during volume change.
• SCI_DECODE_TIME only cleared at hardware and software reset to allow files to be
played back-to-back or looped.
Version: 1.22, 2014-12-19 86