Preliminary Information

MT9196

7-149

Note: Bits marked "-" are reserved bits and should be written with logic "0".

HiEN, LoEN

When high, the programmed tone, for the respective high or low group, is generated. When low, tone generation is

disabled for the respective low or high group.

DTMF St EN

When high, programmed DTMF is muxed into the receive path replacing the receive PCM signal. When low, the

receive path functions normally.

Ring EN

When high, the tone ringer generator is enabled using the coefficients at addresses 1Ah and 1Bh as well as the WR

control bit. For the ringer tone to be applied to the loudspeaker the proper path must be selected via the Receive

Path Control Register (address 13h). When low, the ring generator circuit is disabled.

WR

When high, the tone ringer circuit will toggle between the two programmed frequencies at a 5 Hz rate. When low, the

tone ringer warble rate is 10Hz.

DTMF/Tone Ringer Control Register

ADDRESS = 18h WRITE/READ VERIFY

Power Reset Value

0000 XXX0

76543210

HiEN

LoEN

DTMF

Ring

--

WR

-

St EN

En

Gain Adjustment (dB)

0

0

0

0

0

0

0

0

1

1

1

1

1

1

1

1

0

0

0

0

1

1

1

1

0

0

0

0

1

1

1

1

0

0

1

1

0

0

1

1

0

0

1

1

0

0

1

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

-24

-21

-18

-15

-12

-9

-6

-3

0

+3

+6

+9

+12

+15

+18

+21

0

0

0

0

0

0

0

0

1

1

1

1

1

1

1

1

0

0

0

0

1

1

1

1

0

0

0

0

1

1

1

1

0

0

1

1

0

0

1

1

0

0

1

1

0

0

1

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

Digital Gain Register

ADDRESS = 19h WRITE/READ VERIFY

Power Reset Value

1000 1000

76543210

The frequency of the low group tone is programmed by writing an 8-bit hexadecimal coefficient at this address according to the following

equation:

Frequency (in Hz) = 7.8125 x COEFF

Where the hexadecimal COEFF is converted into a decimal integer between 0 and 255. Frequency resolution is 7.8125Hz in the range

0 to 1992 Hz.

Low Tone Coefficient Register

ADDRESS = 1Ah WRITE/READ VERIFY

Power Reset Value

0000 0000

76543210

L7

L6

L5

L4

L3

L2

L1

L0