sta381bw STMicroelectronics, sta381bw Datasheet - Page 123

• Manufacturer Part Number: sta381bw
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

STA381BW
As an example if CH3VOL = 0x00 or +48 dB and MVOL = 0x18 or -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
mute (CxM) 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 (approximately 96 kHz).
A “hard (instantaneous) 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 whose total volume is less than -80 dB
is muted.
All changes in volume take place at zero-crossings when ZCE = 1
(addr
transitions. When ZCE = 0, volume updates occur immediately.
Table 133. Master volume offset as a function of MVOL[7:0]
Table 134. Channel volume as a function of CxVOL[7:0]
0x04)) on a per-channel basis as this creates the smoothest possible volume
11101100 (0xEC)
11101101 (0xED)
01001100 (0x4C)
11111110 (0xFE)
11010111 (0xD7)
11011000 (0xD8)
11011001 (0xD9)
11011010 (0xDA)
11111111 (0xFF)
01011111 (0x5F)
11111111 (0xFF)
00000000 (0x00)
00000001 (0x01)
00000010 (0x02)
00000000 (0x00)
00000001 (0x01)
00000010 (0x02)
01100000 (0x60)
01100001 (0x61)
CxVOL[7:0]
MVOL[7:0]
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Doc ID 018835 Rev 2
Register description: Sound Terminal compatibility
Volume offset from channel value
Hard channel mute
Hard channel mute
Hard master mute
-127.5 dB
+47.5 dB
-59.5 dB
Volume
+0.5 dB
-0.5 dB
+48 dB
+47 dB
-0.5 dB
-38 dB
-60 dB
-61 dB
-62 dB
-80 dB
-1 dB
0 dB
0 dB
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(Configuration register E
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