CMX649E3 CML Microcircuits, CMX649E3 Datasheet - Page 26

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

ADM Codec
Data Filter
Bandwidth
(Bit 0)
CODEC INTERRUPT CONTROL Register ($81)
Encoder Control
(Bits 7 – 4)
Decoder Control
(Bits 3 – 0)
DECODER MODE AND SETUP Register ($D0)
Decimation
Rate (by 4/8)
(Bit 15)
PCM Input
Select
(Bits 14 – 13)
2002 CML Microsystems Plc
Bit 7
Bit 3
0
1
1
1
1
0
1
1
1
1
Bit 2
Bit
Setting this bit to a logic 1 forces the data filter to narrow mode.
The decoder PCM filter functions as an interpolator for the DAC when PCM words
are being received by the decoder and as a decimator when the decoder is receiving
delta modulation. In the case where delta modulation is received, transcoded PCM
values are available in the DECODE LINEAR PCM OUTPUT Register ($D6) at the
decimation rate. When PCM is received the device can be set to transcode to an
ADM stream available in the DECODE ADM OUTPUT Register ($DA) at the
interpolated rate. A logic 1 sets the interpolation (decimation) rate to 4 (1/4
rate). A logic 0 sets the interpolation (decimation) rate to 8 (1/8
Allows selection of the input to the PCM rate converting filter.
X
X
X
6
0
1
X
X
X
0
1
Bit 5
Bit 1
X
X
X
0
1
X
0
X
1
X
Bit 14
0
Bit 4
Bit 0
X
X
X
X
0
X
X
1
0
1
Bit 13
Encoder is disabled and reset.
Encoder is enabled to run without generating IRQs.
Encoder is enabled and will generate IRQ’s to
indicate VAD status changes.
Encoder is enabled and will generate periodic
IRQs to indicate whether PCM data is available or
needed when transcoding.
Encoder is enabled and will generate periodic
IRQs to indicate whether ADM data is available or
needed when transcoding.
Decoder is disabled and reset.
Decoder is enabled to run without generating IRQs.
Decoder is enabled and will generate IRQs to
indicate VAD status changes.
Decoder is enabled and will generate periodic
IRQs to indicate whether the PCM data is needed
or available when transcoding.
Decoder is enabled and will generate periodic
IRQs to indicate whether the ADM data is needed
or available when transcoding.
X
PCM filter decimates ADM estimator output.
26
Encoder Setting
Decoder Setting
Selected PCM Input
th
the bit rate).
th
the bit
CMX649
D/649/1