DB829 Datasheet, PDF (10/29 Pages) CML Microcircuits – Low Voltage Operation

Baseband Signal Processor
10
MX829 PRELIMINARY INFORMATION
DTMFEN
(Bit 6)
When this bit is "1", the DTMF output is enabled.
When this bit is "0", the DTMF output is disabled. As the powersave of the DTMF is performed in the
DTMFHI and DTMFLO registers, this bit allows a fast start up time for the tones.
Note: The DTMF Encoder and MSK Tx cannot both be enabled at the same time. If both DTMFEN and MSKTX are "1",
then both will be disabled.
DTMFHI
(Bit 5)
DTMFLO
(Bit 4)
DTMF3, DTMF2,
DTMF1, DTMF0
(Bit 3, Bit 2,
Bit 1, Bit 0)
When this bit is "1", the DTMF high frequency tone generator is enabled. It will not appear on the
output pin unless or until the DTMFEN is "1".
When this bit is "0", the DTMF high frequency tone generator is disabled (i.e. powersaved).
When this bit is "1", the DTMF low frequency tone generator is enabled. It will not appear on the
output pin unless or until the DTMFEN is "1".
When this bit is "0", the DTMF low frequency tone generator is disabled (i.e. powersaved).
These four bits define the DTMF tones according to the table below:
Bit 3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Bit 2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Bit 1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
DTMF Tones
1209Hz + 697Hz
1209Hz + 770Hz
1209Hz + 852Hz
1209Hz + 941Hz
1337Hz + 697Hz
1337Hz + 770Hz
1337Hz + 852Hz
1337Hz + 941Hz
1478Hz + 697Hz
1478Hz + 770Hz
1478Hz + 852Hz
1478Hz + 941Hz
1634Hz + 697Hz
1634Hz + 770Hz
1634Hz + 852Hz
1634Hz + 941Hz
DTMF 'Digit'
1
4
7
*
2
5
8
0
3
6
9
#
A
B
C
D
© 1998 MX•COM Inc.
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