Cirrus Logic CS3308 - Manual (Page 20)

20 DS702F1
CS3308
Table 1 shows example volume settings using individual and master volume controls.
Refer to Figure 6 on page 18 for a graphical representation of the volume controls’ functionality.
5.5.3 Volume Limits
The analog section of the CS3308 is designed to accommodate gain and attenuation over the range of
+22 dB to -96 dB. Values outside this range may, however, be written to the CS3308’s internal registers.
As shown in
Figure 6 on page 18 , the value of the Individual and Master volume control registers are
summed before being limited to the range allowed by the CS3308’s analog section. This architecture has
the benefit of allowing both individual and master volume control input beyond the analog range of the
CS3308.
If the effective volume (See Equation 1 on page 19 ) of an individual channel is greater than +22 dB, the
channel’s volume will be set to +22 dB.
If the effective volume of an individual channel is less than -96 dB, the channel will mute, but the MuteChX
bit will not be set. When the channel’s effective volume returns to -96 dB or above, the mute condition will
be released. It should be noted that if the channel’s MuteChX bit or any of the channel’s unmasked
Master X Mute bits are set, the channel will remain muted until the necessary mute conditions are re-
leased.
Individual
ChX
Master 1 Mask 1
ChX
Master 2 Mask 2
ChX
Master 3 Mask 3
ChX
Level
ChX
Channel 1 +3.75 dB
+1.0 dB
0
+5.25 dB
0
-8.5 dB
0 +3.75 dB
Channel 2 +2.5 dB 0 0 1 -6.0 dB
Channel 3 +1.25 dB 0 1 0 +6.5 dB
Channel 4 0 dB 0 1 1 -3.25 dB
Channel 5 -1.25 dB 1 0 0 -0.25 dB
Channel 6 -2.5 dB 1 0 1 -10.0 dB
Channel 7 -3.75 dB 1 1 0 +2.5 dB
Channel 8 -4.0 dB 1 1 1 -6.25 dB
Table 1. Example Volume Settings
Referenced Control Register Location
Master X Volume................. “Master 1 Volume - Address 11h” on page 36
“Master 2 Volume - Address 14h” on page 37
“Master 3 Volume - Address 17h” on page 38
Master X Control ................. “Master 1 Control - Address 12h” on page 37
“Master 2 Control - Address 15h” on page 38
“Master 3 Control - Address 18h” on page 39
Master X Mask .................... “Master 1 Mask - Address 10h” on page 36
“Master 2 Mask - Address 13h” on page 37
“Master 3 Mask - Address 16h” on page 38
Referenced Control Register Location
MuteChX ............................. “Mute Control - Address 0Ah” on page 33
Master X Mute..................... “Master 1 Mute (Bit 1)” on page 37
“Master 2 Mute (Bit 1)” on page 38
“Master 3 Mute (Bit 1)” on page 39