SI2493-C-FT Silicon Laboratories Inc, SI2493-C-FT Datasheet - Page 76

• Manufacturer Part Number: SI2493-C-FT
• Description: 56 KBPS, V.92 ISOMODEM SYSTEM-SIDE - LEAD-FREE TSSOP 0 TO 7
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FT

• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.29, V.32, V.34, V.90, V.92, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: Parallel
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AN93
3.3.14. U17–U30 (Busy Tone Detect Filter Registers)
U17–U2A set the biquad filter coefficients for stages 1–
4 of the Busy Tone detect filter, and U2B, U2C, and U2D
set the Busy Tone detect output scalar on threshold and
off
thresholds are empirically found scalars and have no
units. These coefficients are programmed as 16-bit 2s
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 values meet FCC
requirements.
U2E, U2F, and U30 set the busy cadence minimum total
time (BMTT), busy cadence delta time (BDLT), and
busy cadence minimum on time (BMOT), respectively.
76
Register
U1A
U1B
U1C
U1D
U1E
U1F
U2A
U2B
U2C
U2D
U2E
U2F
U17
U18
U19
U20
U21
U22
U23
U24
U25
U26
U27
U28
U29
U30
threshold,
BT1A0
BT1B1
BT1B2
BT1A2
BT1A1
BT2A0
BT2B1
BT2B2
BT2A2
BT2A1
BT3A0
BT3B1
BT3B2
BT3A2
BT3A1
BT4A0
BT4B1
BT4B2
BT4A2
BT4A1
BMOT
Name
BTON
BTOF
BMTT
BDLT
BTK
respectively
Busy tone detect filter stage 1 biquad coefficients.
Busy tone detect filter stage 2 biquad coefficients.
Busy tone detect filter stage 3 biquad coefficients.
Busy tone detect filter stage 4 biquad coefficients.
Busy tone detect filter output scaler.
Busy tone detect ON threshold.
Busy tone detect OFF threshold.
Busy cadence minimum total time in seconds multiplied by 7200.
Busy cadence delta time in seconds multiplied by 7200.
Busy cadence minimum on time in seconds multiplied by 7200.
Table 35. U17–U30 (Busy Tone Detect Registers)
(see
Table 35).
The
Rev. 0.9
Description
Settings for busy cadences are specified as a range for
ON time (minimum ON and maximum ON) and a range
for OFF time (minimum OFF and maximum OFF). The
three values represented by BMTT, BDLT, and BMOT
fully specify these ranges. BMTT (minimum total time) is
equal to the minimum ON time plus the minimum OFF
time. BDLT (allowable delta) is equal to the maximum
total time (maximum ON time plus the maximum OFF
time) minus the minimum total time (BMTT). BMOT is
the minimum ON time. The values stored in the
registers are the hexadecimal representation of the
times in seconds multiplied by 7200. Default values
meet FCC requirements (see Figure 15 on page 78).
0xC4F4
0xB50A
Default
0x00A0
0x6EF1
0xC000
0x00A0
0x78B0
0xC305
0x70D2
0xC830
0x80E2
0x00A0
0x0800
0x0000
0x0000
0x0000
0x0000
0x0000
0x4000
0x0400
0x4000
0x0009
0x0070
0x0870
0x25F8
0x0438