RALCWI Vocoder
CMX608/CMX618/CMX638
EFRAMEDATA register address $38
15
Type
14
13
X
12
X
11
10
Data
9
8
7
6
5
4
3
2
Data
1
0
This read-only register contains extra information about the last 20ms frame of audio that was
encoded. The data in this register becomes valid after bit 1 in the STATUS register ($40) is set.
The data will remain valid until the next 20ms frame of audio has been encoded.
The Vocoder can produce frames containing either voice, DTMF, or single tones depending on
which bits are set in the VCTRL register ($11). If the Vocoder is set up to detect DTMF and/or
single tones in the audio stream, the DTMF code or the single tone frequency will be reported in
this register.
Bits 0 to 11
Data
This field contains either the DTMF code (bits 0 to 3) or the single tone frequency
that was detected in the audio stream
Bits 12 to 13 Reserved. The value of these two bits should be ignored.
Bits 14 to 15 This field indicates what sort of data is contained in the data field, as shown in the
Type
table below:
Bit 15
Bit 14
Data Type
0
0
0
1
The frame is encoded audio. The data field should be ignored.
The frame contains DTMF. The data field contains the DTMF code in bits 0 to
3 (bit 3 is the msb). If the device is sending DTMF frames as a result of writing
to the SDTMF register, bits 4 to 7 contain the remaining count of DTMF
frames to be sent. If the device is sending DTMF frames as a result of
detecting DTMF in the audio stream, all the other bits should be ignored.
The format of the DTMF data is specified by bit 7 (DTMFF) of the VCFG
register ($07).
Please refer to section 6.2 for the DTMF bit patterns.
1
1
0
1
The frame contains a single tone. The data field contains the single tone's
frequency in Hz. The frequency value has a resolution of 32Hz and bit 11 is
the msb.
Not used.
2012 CML Microsystems Plc
54
D/608_18_38/10
CMLMICRO [ CML MICROCIRCUITS ]
