Data Sheet

PRELIMINARY
VS1063a Datasheet
10 OPERATION
Bit Usage
0 SBR present
1 upsampling active
2 PS present
3 PS active
Bits 7 to 4 in can be used to control the SBR and PS decoding. Bits 5 and 4 select
SBR mode and bits 7 and 6 select PS mode. These configuration bits are useful if your AAC
license does not cover SBR and/or PS.
config1(5:4) Usage
’00’ normal mode, upsample <24 kHz AAC files
’01’ do not automatically upsample <24 kHz AAC files, but
enable upsampling if SBR is encountered (default)
’10’ never upsample
’11’ disable SBR (also disables PS)
config1(7:6) Usage
’00’ normal mode, process PS if it is available
’01’ process PS if it is available, but in downsampled mode
’10’ reserved
’11’ disable PS processing
indicates the current spectral band replication (SBR) and parametric stereo
(PS) mode in the same format as the SBR and PS bits.
AAC decoder can also increase the internal clock automatically when it detects that a file can
not be decoded correctly with the current clock. The maximum allowed clock is configured with
the SCI_CLOCKF register.
If even the highest allowed clock is too slow to decode an AAC file with SBR and PS compo-
nents, the advanced decoding features are automatically dropped one by one until the file can
be played. First the parametric stereo processing is dropped (the playback becomes mono).
If that is not enough, the spectral band replication is turned into downsampled mode (reduced
bandwidth). As the last resort the spectral band replication is fully disabled. Dropped features
are restored at each song change.
Version: 0.42, 2011-11-24 74