CMX649 CML Microcircuits, CMX649 Datasheet - Page 27

• Manufacturer Part Number: CMX649
• Description: ADM Codec
• Manufacturer: CML Microcircuits

ADM Codec
Decoder VAD
Decay Time
Constant
(Bits 7 – 5)
Decoder VAD
Attack Time
Constant
(Bits 4 – 3)
Decoder VAD
Output Source
(Bits 2 – 1)
Reserved
(Bit 0)
DECODE ADM CONTROL Register ($D1)
Syllabic Time
Constant
(Bits 15 – 13)
2003 CML Microsystems Plc
Allows selection of the Voice Activity Detector decay time constant.
Allows selection of the Voice Activity Detector attack time constant.
Allows selection of the Voice Activity Detector output source.
This bit is reserved and should be set to a logic 0.
Step size integrator Loss Coefficient: allows selection of syllabic time constant.
Bit 15
0
0
0
0
1
1
1
1
Bit 7
Bit 2
0
0
0
0
1
1
1
1
0
0
1
1
Bit 4
Bit 14
0
0
1
1
0
0
1
1
0
0
1
1
Bit 6
Bit 1
0
0
1
1
0
0
1
1
0
1
0
1
Bit 3
Bit 13
0
1
0
1
0
1
0
1
0
1
0
1
27
Normal VAD operation.
ADM bits are driven over VAD pin at
the ADM bit rate (may be useful when
transcoding or verifying proper
application of the burst interface).
VAD output driven to 0.
VAD output driven to 1.
Bit 5
0
1
0
1
0
1
0
1
(VAD Decay Time Constant)/4
(VAD Decay Time Constant)/8
(VAD Decay Time Constant)/16
(VAD Decay Time Constant)/32
512/(3*Bit Rate)
768/(3*Bit Rate)
1024/(3*Bit Rate)
1536/(3*Bit Rate)
2048/(3*Bit Rate)
3072/(3*Bit Rate)
Bluetooth compatible when running at
64kbps.
4096/(3*Bit Rate)
6144/(3*Bit Rate)
Attack Time Constant (ms)
Syllabic Filter Time Constant (ms)
128/(Bit Rate)
256/(Bit Rate)
512/(Bit Rate)
1024/(Bit Rate)
2048/(Bit Rate)
4096/(Bit Rate)
8192/(Bit Rate)
16384/(Bit Rate)
Decay Time Constant (ms),
VAD Output
Bit Rate in kbps
CMX649
D/649/2