Baseband Signal Processor

10

MX829 PRELIMINARY INFORMATION

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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)

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).

DTMFLO

(Bit 4)

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).

DTMF3, DTMF2,

DTMF1, DTMF0

(Bit 3, Bit 2,

Bit 1, Bit 0)

These four bits define the DTMF tones according to the table below:

Bit 3

Bit 2

Bit 1

Bit 0

DTMF Tones

DTMF 'Digit'

0000

1209Hz + 697Hz

1

0001

1209Hz + 770Hz

4

0010

1209Hz + 852Hz

7

0011

1209Hz + 941Hz

*

0100

1337Hz + 697Hz

2

0101

1337Hz + 770Hz

5

0110

1337Hz + 852Hz

8

0111

1337Hz + 941Hz

0

1000

1478Hz + 697Hz

3

1001

1478Hz + 770Hz

6

1010

1478Hz + 852Hz

9

1011

1478Hz + 941Hz

#

1100

1634Hz + 697Hz

A

1101

1634Hz + 770Hz

B

1110

1634Hz + 852Hz

C

1111

1634Hz + 941Hz

D