VS1103B Datasheet, PDF (35/61 Pages) List of Unclassifed Manufacturers – MIDI/ADPCM AUDIO CODEC

VLSI
Solution ^y
VS1103b
VS1103B
6. FUNCTIONAL DESCRIPTION
6.6.12 SCI MIXERVOL (RW)
Control mixer volume. The contents of this register is as follows:
SCI MIXERVOL bits
Name
Bits Description
SMV ACTIVE 15 Control active
SMV GAIN3 14:10 Gain 3
SMV GAIN2 9:5 Gain 2
SMV GAIN1 4:0 Gain 1
Gain values are defined in 1 dB steps so that 25 corresponds to 0 dB (signal is passed on as is) and 31 is
+6 dB (signal is doubled). 0 means the channel is disabled.
If SMV ACTIVE is 0, then Gain 1 is set to 25 (0 dB), and both Gain 2 and Gain 3 are set to 0 (mute).
See Figure 12 on page 26 for more details on where gains are applied.
Note: The polarity of the gains are opposite to registr SCI VOL: higher means a higher gain, not higher
attenuation.
6.6.13 SCI ADPCMRECCTL (RW)
Name
SARC DREQ512
SARC OUTOFADPCM
SARC MANUALGAIN
SARC GAIN4
SCI ADPCMRECCTL bits
Bits Description
8 If set, DREQ needs 512 byte space to turn on.
7 If set, current ADPCM playback is canceled.
6 If set, automatic gain control (AGC) is not in used.
5:0 If SARC MANUALGAIN is 1, this is Gain 4;
otherwise it is maximum gain of AGC
SARC DREQ512 affects how the DREQ pin works. If not set, when DREQ is active there is at least 32
bytes space to write to. If set, DREQ is set only when there is at least 512 bytes of free space in the SDI
input buffer.
SARC OUTOFADPCM does same to ADPCM playback as SCI MODE register bit SM OUTOFMIDI
does to MIDI playback. Thus, if you want to stop decoding an ADPCM file, set SARC OUTOFADPCM,
and send data until SARC OUTOFADPCM is cleared.
SARC MANUALGAIN controls whether Gain 4 is manual or automatic.
If SARC MANUALGAIN is set to 1, SARC GAIN4 sets Gain 4. Otherwise SARC GAIN4 sets the
maximum gain allowed for the automatic gain control. The value is set at 1 dB steps and value 25 means
0 dB gain (signal is passed on without change). 31 is equal to to +6 dB gain, etc. 0 disables the signal
path completely.
Version 1.01, 2007-09-03
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