MT9094 Datasheet, PDF (19/32 Pages) Mitel Networks Corporation – ISO2-CMOS ST-BUS™ FAMILY Digital Telephone (DPhone-II)

MT9094
Tone Coeff Register 1-DTMF or Tone Ringer
ADDRESS = 23h WRITE/READ VERIFY
B7 B6 B5 B4 B3 B2 B1 B0
Power Reset Value
0000 0000
7
6
5
4
3
2
1
0
This register is used to program the low-group frequency of the DTMF program. The tone coefficient is calculated as follows:
COEF = 0.128 x Frequency
where: Frequency is in Hz (note: COEF must be converted to an 8 bit binary integer)
Highest frequency possible:
1992.2 Hz
Lowest frequency possible:
7.8 Hz
Frequency resolution:
7.8 Hz
Pre-twist:
-2.1dB ± 0.2dB
This register is used to program the first frequency of the squarewave ringer program. The tone coefficient is calculated as follows:
COEF = 8000 / Frequency
where: Frequency is in Hz (note: COEF must be rounded off and converted to an 8 bit binary integer)
Highest frequency possible:
4000 Hz
Lowest frequency possible:
31.4 Hz
Frequency resolution:
non-linear
This tone can be disabled by writing zero to this register for single tone generation.
Tone Coeff Register 2-DTMF or Tone Ringer
ADDRESS = 24h WRITE/READ VERIFY
B7 B6 B5 B4 B3 B2 B1 B0
Power Reset Value
0000 0000
7
6
5
4
3
2
1
0
This register is used to program the high-group frequency of the DTMF program. The tone coefficient is calculated as follows:
COEF = 0.128 x Frequency
where: Frequency is in Hz (note: COEF must be converted to an 8 bit binary integer)
Highest frequency possible:
1992.2 Hz
Lowest frequency possible:
7.8 Hz
Frequency resolution:
7.8 Hz
Pre-twist:
0dB
This register is used to program the second frequency of the squarewave program. The tone coefficient is calculated similarly to tone
coefficient register 1.
ADDRESS 25h is RESERVED
Tone Ringer Warble Rate-Tone Ringer
ADDRESS = 26h WRITE/READ VERIFY
B7 B6 B5 B4 B3 B2 B1 B0
Power Reset Value
0000 0000
7
6
5
4
3
2
1
0
The tone ringer will switch between squarewave frequencies at a warble frequency defined by this register. The relationship between
the duration period of each tone and the 8 bit warble coefficient is as follows:
Tone duration (warble frequency) = 500 / COEF
where: Frequency is in Hz, and 0≤COEF <256
Highest frequency possible:
500 Hz
Lowest frequency possible:
2.0 Hz
Addresses: 27h to 2Dh are transmit and receive gains and coefficients used by the filters in the handsfree
decision circuit.
2Eh to 3Fh are scratch-pad ram locations used by the DSP algorithms as temporary storage dur-
ing calculations.
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