Datasheet

STA333W Register description
Doc ID 13365 Rev 2 33/49
6.2.2 Master volume register (addr 0x07)
6.2.3 Channel volume (addr 0x08, 0x09)
Volume setting
The volume structure of the STA333W consists of individual volume registers for each
channel and a master volume register that provides an offset to each channels 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 or +48 dB and MV = 0x18 or -12 dB, then the total gain
for channel 3 = +36 dB.
The master mute when set to 1 will mute all channels at once, whereas the individual
channel mutes (CxM) mute 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 (about 96 kHz). A hard mute can be
obtained by commanding a value of all 1’s (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 (configuration register F)
on a per channel basis as this creates the smoothest possible volume transitions. When
ZCE = 0, volume updates will occur immediately.
D7 D6 D5 D4 D3 D2 D1 D0
MV7 MV6 MV5 MV4 MV3 MV2 MV1 MV0
11111111
D7 D6 D5 D4 D3 D2 D1 D0
C1V7 C1V6 C1V5 C1V4 C1V3 C1V2 C1V1 C1V0
01100000
D7 D6 D5 D4 D3 D2 D1 D0
C2V7 C2V6 C2V5 C2V4 C2V3 C2V2 C2V1 C2V0
01100000
Table 41. Master volume offset as a function of MV
MV[7:0] Volume offset from channel value
00000000 (0x00) 0 dB
00000001 (0x01) -0.5 dB
00000010 (0x02) -1 dB
……
01001100 (0x4C) -38 dB
……
11111110 (0xFE) -127.5 dB
11111111 (0xFF) Hard master mute