SI3230 Datasheet, PDF (93/108 Pages) Silicon Laboratories – PROSLIC® PROGRAMMABLE CMOS SLIC WITH RINGING/BATTERY VOLTAGE GENERATION

Si3230
Table 32. DTMF Indirect Registers Description (Continued)
Addr.
Description
2 DTMF Row 2 Peak Magnitude Pass Ratio Threshold.
This register sets the minimum power ratio threshold for row 2 DTMF detection. If the ratio of
power in row 2 to total power in the row band is greater than ROW2, then a row 2 signal is
detected. A value of 0x7FF0 corresponds to a 1.0 ratio.
3 DTMF Row 3 Peak Magnitude Pass Ratio Threshold.
This register sets the minimum power ratio threshold for row 3 DTMF detection. If the ratio of
power in row 3 to total power in the row band is greater than ROW3, then a row 3 signal is
detected. A value of 0x7FF0 corresponds to a 1.0 ratio.
4 DTMF Column Peak Magnitude Pass Threshold.
This register sets the minimum power ratio threshold for column DTMF detection; all col-
umns use the same threshold. If the ratio of power in a particular column to total power in the
column band is greater than COL, then a column detect for that particular column signal is
detected. A value of 0x7FF0 corresponds to a 1.0 ratio.
5 DTMF Forward Twist Threshold.
This register sets the threshold for the power ratio of row power to column power. A value of
0x7F0 corresponds to a 1.0 ratio.
6 DTMF Reverse Twist Threshold.
This register sets the threshold for the power ratio of column power to row power. A value of
0x7F0 corresponds to a 1.0 ratio.
7 DTMF Row Ratio Threshold.
This register sets the threshold for the power ratio of highest power row to the other rows. A
value of 0x7F0 corresponds to a 1.0 ratio.
8 DTMF Column Ratio Threshold.
This register sets the threshold for the power ratio of highest power column to the other col-
umns. A value of 0x7F0 corresponds to a 1.0 ratio.
9 DTMF Row Second Harmonic Threshold.
This register sets the threshold for the power ratio of peak row tone to its second harmonic.
A value of 0x7F0 corresponds to a 1.0 ratio.
10 DTMF Column Second Harmonic Threshold.
This register sets the threshold for the power ratio of peak column tone to its second har-
monic. A value of 0x7F0 corresponds to a 1.0 ratio.
11 DTMF Power Minimum Threshold.
This register sets the threshold for the minimum total power in the DTMF calculation, under
which the calculation is ignored.
12 DTMF Hot Limit Threshold.
This register sets the two-step AGC in the DTMF path.
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Preliminary Rev. 0.96
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