Cirrus Logic CS6422 - Manual (Page 21)

CS6422
21
3.5.7 RDSRMP - RX DOUBLE-TALK SUPPRESSION RAMP RATE
When “Rx Double-talk Suppression attenuation” (RDbtS, Register 3) is set to a non-zero value, the
CS6422 will introduce a programmable amount of attenuation into the receive path during a double-
talk event. RDSRmp controls the decay rate of the receive double-talk attenuation (the attack rate is
~40 ms).
The ‘slow’ setting of RDSRmp results in an attenuation decay rate of about 1 second. The ‘normal’
setting of RDSRmp results in an attenuation decay rate of about 100 ms.
3.5.8 IDLTX - HALF-DUPLEX IDLE RETURN-TO-TRANSMIT
When IdlTx is enabled, the CS6422’s half-duplex engine will automatically switch into <Transmit>
mode from the <Idle> state. The <Idle> state is entered when the previously active channel has been
silent for the time period set by HDly (half-duplex Holdover Delay) in Register 2.
The use of IdlTx permits a full-duplex-like behavior when operating in half-duplex at the beginning of
a call. This benefit is most noticeable when the listener at the far end is using a handset.
When TSMde is set to ‘0’ (Noise Guard enabled), IdlTx is usually disabled. IdlTx is disabled by de-
fault.
CS6422
DS295F1 21