CMX649 CML Microcircuits, CMX649 Datasheet - Page 32

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

ADM Codec
ADM Output
Select
(Bit 0)
ENCODE ADM CONTROL Register ($E1)
Syllabic Time
Constant
(Bits 15 – 13)
Dynamic Range
for Step Size
Integrator
Step Size
Integrator
(Bits 12 – 10)
Companding
Rule
(Bits 9 – 8)
2003 CML Microsystems Plc
For normal operation this bit should be set to a logic 0. Setting this bit to a logic 1
allows arbitrary ADM streams, written in via the ENCODE ADM INPUT Register
($E8), to be output. For example to force the encoder to output an idle pattern
010101… while running, regardless of the input analog waveform, write $55 into
register $E8 and set this bit to a logic 1.
Step size integrator Loss Coefficient: allows selection of syllabic time constant.
Numbers given for maximum and minimum step size are based on 16-bit word
length (-32768 to 32767).
This is the number of consecutive ones or zeros that must occur for the step size to
be adjusted.
Bit 15
Bit 12
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Bit 14
Bit 11
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 9
Bit 13
Bit 10
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Bit 8
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)
Syllabic Filter Time Constant (ms),
Maximum Step
0
1
0
1
32
10240
10240
5120
5120
2560
2560
1280
1280
Bluetooth compatible when
running at 64kbps.
Bit Rate in kbps
Companding Rule
3 of 3
4 of 4
5 of 5
6 of 6
Bluetooth
compatible when
running at 64kbps.
Minimum Step
20
10
20
10
20
10
20
10
CMX649
D/649/2