CS3318 Datasheet, PDF (21/44 Pages) Cirrus Logic – 8-Channel Analog Volume Control

CS3318
5.6 Muting Controls
The CS3318 provides flexible muting capabilities to complement its comprehensive volume control abilities.
Each channel’s mute state may be controlled on an individual channel basis, by any of 3 master mute con-
trols, and by the hardware MUTE input pin.
The mute state of any channel within the CS3318 is determined by the logical OR of four conditions, and
the channel will mute if any one or more of the conditions are met. These conditions are:
1. The channel’s individual mute condition is set.
2. One or more of the channel’s unmasked master mute conditions are set.
3. The hardware mute input is enabled and active.
4. The channel’s effective volume (See Equation 1 on page 19) is less than -96 dB.
The CS3318 incorporates zero-crossing detection capabilities, and all muting changes are implemented as
dictated by the zero-crossing detection settings (see “Zero-Crossing Detection” on page 22).
5.6.1
Individual Channel Mute Controls
The CS3318 provides 8 individual channel mute controls. These controls can be used to individually mute
each of the input/output channels independent of all other volume and mute settings.
Individual channel mute control is accomplished by setting or clearing the channel’s corresponding
MuteChX bit in the Mute Control register.
Referenced Control
Register Location
MuteChX ............................. “Mute Control - Address 0Ah” on page 33
5.6.2
Master Mute Controls
The CS3318 master mute controls allow the user to simultaneously control the mute state of all channels,
or a user-defined subset of all channels within a device. A total of 3 master mute controls, M1_Mute,
M2_Mute, and M3_Mute, are provided for comprehensive and flexible control.
Master mute control is accomplished by setting or clearing the MX_Mute bit in the corresponding Master
Control register. Each master mute control affects only those channels unmasked in its corresponding
Master X Mask register.
Referenced Control
Register Location
MX_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
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
5.6.3
Hardware Mute Control
The CS3318 implements a hardware MUTE input pin to allow the user to control the mute state of all chan-
nels with an external level-active signal. By default, the MUTE input is configured for active low operation,
and all channels will be held in a mute state whenever this input is low.
For enhanced flexibility, setting the MutePolarity bit will configure the MUTE input pin for active high op-
eration. Additionally, the EnMuteIn bit may be cleared to disable the CS3318’s response to the MUTE in-
put signal.
Referenced Control
Register Location
MutePolarity ........................ “MUTE Input Polarity (Bit 4)” on page 33
EnMuteIn............................. “Enable MUTE Input (Bit 5)” on page 33
DS693F1
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