Baseband Processor For Mixed Mode Land Mobile Radio
CMX880
DTMF Tones:
The DTMF tone pairs to be generated and tone levels are defined by the ‘DTMF TX AND TONE LEVEL’ register
($CD). The DTMF tones must be transmitted on their own, so if a voice signal is being transmitted, this must be
disabled for the duration of the DTMF tones transmission. The user/host mC must disable the voice path prior to
initiating transmission of the DTMF tones, and restore the voice path after the DTMF transmission is complete.
Table 12 shows valid DTMF tone pairs, together with the values for programming the ‘Tone Pair’ field of the
‘DTMF TX AND TONE LEVEL’ register. No other tone pair combinations are programmable.
Table 12 DTMF Tone Pairs and Corresponding Tx Programming Codes
Tone Pair
Key Pad Position
High Tone
Programming
Low Tone
Code (Hex)
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
1
2
3
4
5
6
7
8
9
0
*
#
A
B
C
D
697Hz
697Hz
697Hz
770Hz
770Hz
770Hz
852Hz
852Hz
852Hz
941Hz
941Hz
941Hz
697Hz
770Hz
852Hz
941Hz
1209Hz
1336Hz
1477Hz
1209Hz
1336Hz
1477Hz
1209Hz
1336Hz
1477Hz
1336Hz
1209Hz
1477Hz
1633Hz
1633Hz
1633Hz
1633Hz
ã 2001 Consumer Microcircuits Limited
32
D/880/1
CMLMICRO [ CML MICROCIRCUITS ]
