Datasheet

VS1053b Datasheet

9 OPERATION

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

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.

9.11.4 Midi

Parameter Address Usage

conﬁg1 0x1e03 Miscellaneous conﬁguration

bits [3:0] Reverb: 0 = auto (ON if clock >= 3.0×)

1 = off, 2 - 15 = room size

bytesLeft 0x1e2a/2b The number of bytes left in this track

The lowest 4 bits of

config1

controls the reverb effect.

9.11.5 Ogg Vorbis

Parameter Address Usage

gain 0x1e2a Preferred replay-gain offset

Ogg Vorbis decoding supports Replay Gain technology. The Replay Gain technology is used

to automatically give all songs a matching volume so that the user does not need to adjust

the volume setting between songs. If the Ogg Vorbis decoder ﬁnds a Replay Gain tag in the

song header, the tag is parsed and the decoded gain setting can be found from the

gain

parameter. For a song without any Replay Gain tag, a default of -6 dB (

gain

value -12) is

used. For more details about Replay Gain, see http://en.wikipedia.org/wiki/Replay_Gain and

http://www.replaygain.org/.

The player software can use the gain value to adjust the volume level. Negative values mean

that the volume should be decreased, positive values mean that the volume should be in-

creased.

Version: 1.13, 2011-05-27 62