CMX649E3 CML Microcircuits, CMX649E3 Datasheet - Page 8

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

ADM Codec
rate. Decoding PCM simply requires interpolation and filtering to compensate for sin(x)/x roll-off of zero
holding the PCM samples. The interpolation ratio can be programmed to 4 or 8.
5.1.3 Transcoding with the Encoder and Decoder
(note that the decoder also can be configured to do this function and in this example
all data is read and written via C-BUS registers $EA ($DA) and $E7 ($D7) respectively (for decoder))
2002 CML Microsystems Plc
DECODER
DECODER
INPUT
OUT
OUT
+
-
REG $D6
OUTPUT
REG $D6
OUTPUT
PCM
PCM
Figure 7 PCM to ADM transcoding with Encoder
Figure 8 ADM to PCM transcoding with Decoder
OUTPUT
REG $E6
PCM
REG $D7
+
REG $D7
+
INPUT
INPUT
PCM
PCM
PCM TO ADM TRANSCODE FEEDBACK
PCM TO ADM TRANSCODE FEEDBACK
+
REG $E7
INPUT
PCM
PCM TO ADM TRANSCODE FEEDBACK
Figure 6 PCM Decoding
1
1
st
st
ENCODER FEEDBACK
ESTIMATOR INTEGRATORS
ESTIMATOR INTEGRATORS
DECODE
REG $D0
1
DECODE
REG $D0
SETUP
SETUP
st
OFFSET NULLING
OFFSET NULLING
ESTIMATOR INTEGRATORS
REGS $D3 & $D5
REGS $D3 & $D5
ENCODE
REG $E0
SETUP
OFFSET NULLING
REGS $E3 & $E5
8
ADM CTL
ADM CTL
REG $D1
REG $D1
2
2
ADM CTL
nd
nd
REG $E1
2
nd
PCM OUT
LINEAR
PCM IN
LINEAR
x
x
x
REGISTER
REGISTER
REGISTER
DELAY
DELAY
DELAY
PROGRAMMABLE
PROGRAMMABLE
PROGRAMMABLE
STEP SIZE
CONTROL
STEP SIZE
CONTROL
STEP SIZE
CONTROL
REG $E8
INPUT
ADM
REG $DA
REG $D8
OUTPUT
REG $DA
REG $D8
OUTPUT
REG $EA
OUTPUT
INPUT
INPUT
ADM
ADM
ADM
ADM
ADM
CMX649
D/649/1
ADM OUT
LINEAR
PCM IN
ADM IN
LINEAR
PCM IN
ADM IN