SI2493-D-FS Silicon Laboratories Inc, SI2493-D-FS Datasheet - Page 97

• Manufacturer Part Number: SI2493-D-FS
• Description: IC ISOMODEM SYSTEM-SIDE 16SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-D-FS

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5.7.2. U00–U16 (Dial Tone Detect Filter Registers)
U00–U13 set the biquad filter coefficients for stages 1–4 of the dial-tone detection filter. U14, U15, and U16 set the
dial-tone detection output scaler, on threshold and off threshold, respectively.
The thresholds are empirically found scalars and have no units. These coefficients are programmed as 16-bit,
two’s complement values. All A0 values are in 3.12 format where 1.0 = 0x1000. All other coefficients are in 1.14
format where 1.0 = 0xC000. Default settings meet FCC requirements. Additionally, register U34 sets the time
window in which a dial tone can be detected. Register U35 sets the minimum time within the U34 window that the
dial tone must be present for a valid detection. See "5.7.5. U34–U35 (Dial Tone Timing Register)" for more
information.
Register
U0A
U0B
U0C
U0D
U0E
U0F
U00
U01
U02
U03
U04
U05
U06
U07
U08
U09
U10
U11
U12
U13
U14
U15
U16
DT1A0
DT1B1
DT1B2
DT1A2
DT1A1
DT2A0
DT2B1
DT2B2
DT2A2
DT2A1
DT3A0
DT3B1
DT3B2
DT3A2
DT3A1
DT4A0
DT4B1
DT4B2
DT4A2
DT4A1
DTON
Name
DTOF
DTK
Dial-tone detection filters stage 1 biquad coefficients.
Dial-tone detection filters stage 2 biquad coefficients.
Dial-tone detection filters stage 3 biquad coefficients.
Dial-tone detection filters stage 4 biquad coefficients.
Dial-tone detection filter output scaler.
Dial-tone detection ON threshold.
Dial-tone detection OFF threshold.
Table 48. U0–U16 (Dial Tone Registers)
Rev. 1.3
Description
AN93
0xC4F4
0xB50A
Default
0x00A0
0x6EF1
0xC000
0x00A0
0x78B0
0xC305
0x70D2
0xC830
0x80E2
0x00A0
0x0800
0x0000
0x0000
0x0000
0x0000
0x0000
0x4000
0x0400
0x4000
0x0009
0x0070
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