ADM Codec
CMX649
Sidetone Level These bits control the gain of the sidetone signal coming from the AAF output to be
(Bits 2 – 1)
summed in with the decode signal at the input to the AIF.
Bit 2
0
0
1
1
Bit 1
0
1
0
1
Gain Setting
0dB
-9dB
-15dB
-21dB
Sidetone Enable When this bit is a logic 1 the sidetone path is enabled with the gain setting controlled
(Bit 0)
as shown above. When this bit is logic 0 the sidetone path is disabled.
AUDIO INPUT LEVEL CONTROL Register ($63)
Audio Input
Level Control
(Bits 7 – 3)
These bits are used to set the gain of the Digitally Controlled Amplifier (DCA) at the
output of the microphone amplifier.
Bit 7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Bit 6
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Bit 5
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Bit 4
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 3
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Audio Input Gain
Off
-7.5dB
-7.0dB
-6.5dB
-6.0dB
-5.5dB
-5.0dB
-4.5dB
-4.0dB
-3.5dB
-3.0dB
-2.5dB
-2.0dB
-1.5dB
-1.0dB
-0.5dB
0.0dB
0.5dB
1.0dB
1.5dB
2.0dB
2.5dB
3.0dB
3.5dB
4.0dB
4.5dB
5.0dB
5.5dB
6.0dB
6.5dB
7.0dB
7.5dB
Reserved
(Bits 2– 0)
These bits are reserved and should be set to a logic 0.
© 2003 CML Microsystems Plc
18
D/649/2