CMX608 datasheet(52/70 Pages) CMLMICRO

52 / 70 page

RALCWI Vocoder

CMX608/CMX618/CMX638

 2014 CML Microsystems Plc

D/608_18_38/11

EFRAMEDATA register address $38

Type

Data

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

This field contains either the DTMF code (bits 0 to 3) or the single tone frequency

Data

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

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

Please refer to section 6.2 for the DTMF bit patterns.

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.

CMX608 Datasheet(PDF) 52 Page - CML Microcircuits