RALCWI Vocoder
CMX608/CMX618/CMX638
Bit 5
DDTMFD
Decoder DTMF Detect: If this bit is set to '1' the decoder will detect the special
DTMF frames. If DTMF is detected, the 4 bit DTMF code will be placed in the
DFRAMEDATA register ($37). If a special DTMF frame is not detected, the frame
will be passed on to the next decoding stage.
If this bit is cleared to '0', special DTMF frame detection will not be done and the
frame will be passed on to the next decoding stage.
Bit 6
DDTMFG
Decoder DTMF Generate: If this bit is set to '1' and the decoder is detecting the
special DTMF frames, the decoder will generate the DTMF tones in the output
audio stream. The level of the generated DTMF may be controlled by the
DTMFATTEN register ($0A).
If this bit is cleared to '0', DTMF tones will not be generated.
This bit is ignored if DTMFD is cleared to '0'.
Bit 7
DSTDD
Decoder STD Detect: If this bit is set to '1' the decoder will detect the special STD
frames. If an STD frame is detected, the frequency (in Hz) will be placed in the
DFRAMEDATA register ($37). If a special STD frame is not detected, the frame
will be passed on to the next decoding stage. See section 6.4 for further details.
If this bit is cleared to '0', special STD frame detection will not be done and the
frame will be passed on to the next decoding stage.
Bit 8
DSTDG
Decoder STD Generate: If this bit is set to '1' and the decoder is detecting the
special STD frames, the decoder will generate the detected tone in the output
audio stream.
If this bit is cleared to '0', the detected single tone will not be generated. This bit is
ignored if DSTDD is cleared to '0'. See section 6.4 for further details.
Bit 9
DSTDP
Decoder STD Priority: Controls the order of frame processing in the decoder.
Single tone detection and DTMF detection are separate states that are performed
on the input frames before being given to the Vocoder to decode.
If this bit is set to '1' the decoder will first try and detect a special STD frame
before a special DTMF frame.
If this bit is cleared to '0', the decoder will first try and detect a special DTMF
frame before a special STD frame.
This bit is only significant if both DSTDD and DDTMFD bits are set to '1'. If either
bit is cleared to '0', then the DSTDP bit is ignored.
Bit 10
This bit must be cleared to '0' for correct operation.
Bit 11
EDTMFD
Encoder DTMF Detect: If this bit is set to '1' the encoder will try and detect DTMF
tones in the input audio stream. If DTMF is detected, the encoder will form a
special DTMF frame and place the detected DTMF code in the EFRAMEDATA
register ($38). If DTMF is not detected the audio will be passed on to the next
stage.
If this bit is cleared to '0', no DTMF detection will be attempted.
If this bit is set to '1', then the DDTMFD bit in the decoder at the other end of the
channel should also be set to '1'.
2014 CML Microsystems Plc
47
D/608_18_38/11
CMLMICRO [ CML MICROCIRCUITS ]
