SI2404 SILABS [Silicon Laboratories], SI2404 Datasheet - Page 42

• Manufacturer Part Number: SI2404
• Description: V.90, V.34, V.32BIS, V.22BIS ISOMODEM WITH GLOBAL DAA
• Manufacturer: SILABS [Silicon Laboratories]

Si2457/34/15/04
6. User-Access Registers (U-Registers)
The :U AT command is used to write these 16-bit U-registers, and the :R command is used to read them.
U-registers are identified by a hexidecimal (hex) address.
42
Register
U0C
U0D
U0A
U0B
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
Description
DT1 registers set the coefficients for stage 1 of the Dial Tone Detect filter.
Default is for FCC countries. See “AN93: Modem Designer’s Guide” for other
country settings.
Dial tone detect filters stage 2 biquad coefficients.
Dial tone detect filters stage 3 biquad coefficients.
Dial tone detect filters stage 4 biquad coefficients.
Dial tone detect filter output scaler.
Dial tone detect ON threshold.
Dial tone detect OFF threshold.
Table 16. U-Register Description
Rev. 1.0
0xC4F4
0xB50A
Default
0x00A0
0x6EF1
0xC000
0x00A0
0x78B0
0xC305
0x70D2
0xC830
0x80E2
0x00A0
0x0800
0x0000
0x0000
0x0000
0x0000
0x0000
0x4000
0x0400
0x4000
0x0009
0x0070