sta335bwqs STMicroelectronics, sta335bwqs Datasheet - Page 45

• Manufacturer Part Number: sta335bwqs
• Description: 2.1-channel High-efficiency Digital Audio System With Qsound Qhd?
• Manufacturer: STMicroelectronics

STA335BWQS
7.7.5
Channel 3 / line output volume
The volume structure of the STA335BWQS consists of separate volume registers for each
channel and a master volume register to provide an offset to each channel volume setting.
The individual channel volumes are adjustable in 0.5 dB steps from +48 dB to -80 dB.
As an example if C3V = 0x00 (+48 dB) and MV = 0x18 (-12 dB) then the total gain for
channel 3 = +36 dB.
The master mute, when set to 1, mutes all channels at once, whereas the individual channel
mutes (CnM) mutes only that channel. Both the master mute and the channel mutes provide
a “soft mute” with the volume ramping down to mute in 4096 samples from the maximum
volume setting at the internal processing rate (~96 kHz).
A “hard mute” can be obtained by programming a value of 0xFF (255) to any channel
volume register or the master volume register. When volume offsets are provided via the
master volume register any channel that whose total volume is less than -80 dB is muted.
All changes in volume take place at zero-crossings when ZCE = 1
(addr 0x05)
transitions. When ZCE=0, volume updates occur immediately.
Table 53.
Table 54.
C3V7
D7
0
01001100 (0x4C)
11111110 (0xFE)
11111111 (0xFF)
01011111 (0x5F)
00000000 (0x00)
00000001 (0x01)
00000010 (0x02)
00000000 (0x00)
00000001 (0x01)
00000010 (0x02)
01100000 (0x60)
01100001 (0x61)
CnV[7:0]
MV[7:0]
on a per channel basis as this creates the smoothest possible volume
Master volume offset as a function of MV[7:0]
Channel volume as a function of CnV[7:0]
…
…
…
C3V6
D6
1
C3V5
D5
1
C3V4
D4
0
Volume offset from channel value
C3V3
D3
0
Hard master mute
-127.5 dB
+47.5 dB
Volume
+0.5 dB
-0.5 dB
+48 dB
+47 dB
-0.5 dB
-38 dB
-1 dB
0 dB
0 dB
…
…
…
C3V2
D2
0
(Configuration register F
Register description
C3V1
D1
0
C3V0
D0
0
45/72