CMX649E3 CML Microcircuits, CMX649E3 Datasheet - Page 28

• Manufacturer Part Number: CMX649E3
• Description: ADM Codec
• Manufacturer: CML Microcircuits

ADM Codec
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)
Dynamic Range
for Step Size
Integrator
(Bits 12 – 10)
2002 CML Microsystems Plc
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.
Maximum and minimum step size are based on 16-bit word length (-32768 to
32767).
Bit 12
Bit 15
0
0
0
0
0
0
0
0
1
1
1
1
Bit 2
0
0
1
1
1
1
0
0
1
1
Bit 11
Bit 4
Bit 14
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 1
Bit 10
1
1
0
0
1
1
0
1
0
1
Bit 3
0
1
0
1
Bit 13
0
1
0
1
0
1
0
1
0
1
0
1
28
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.
Maximum Step
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)
10240
10240
5120
5120
512/(Bit Rate)
1024/(Bit Rate)
2048/(Bit Rate)
4096/(Bit Rate)
8192/(Bit Rate)
16384/(Bit Rate)
VAD Output
Minimum Step
20
10
20
10
CMX649
D/649/1