SI2456 Datasheet, PDF (44/86 Pages) Silicon Laboratories – V.90, V.34, V.32BIS ISOMODEM™ WITH INTEGRATED GLOBAL DAA

Si2456/Si2433/Si2414
Table 21. U-Register Description (Continued)
Register Address
(Hex)
U2E 0x002E
U2F
0x002F
U30
0x0030
U31
0x0031
U32
U33
U34
U35
U37
U38
U39
U3A
U3B
U3C
U3D
U3E
U3F
U40
U42
0x0032
0x0033
0x0034
0x0035
0x0037
0x0038
0x0039
0x003A
0x003B
0x003C
0x003D
0x003E
0x003F
0x0040
0x0042
Name Description
Default
BMTT
BDLT
Busy cadence minimum total time in seconds multiplied by 7200.
Country-specific settings for busy, ringback, and dialtone cadences
are specified by a range for ON time (minimum ON and maximum
ON) and a range for OFF time (minimum OFF and maximum OFF).
The Si2456/33/14 uses three registers to fully specify this range:
MTT, DLT, and MOT. MTT is the minimum total time and is equal to
the minimum ON time plus the minimum OFF time. DLT is the allow-
able delta. This is equal to maximum total time (maximum ON time
plus the maximum OFF time) minus the minimum total time (MTT).
MOT is simply the minimum ON time.
Example: A country specifies a busy tone with ON time from 1–2
seconds and OFF time from 3–4 seconds. Thus, minimum ON time
= 1 sec, maximum ON time = 2 sec, minimum OFF time = 3 sec,
and maximum OFF time = 4 sec. BMTT = 1 + 3 = 4 seconds, maxi-
mum total time = 2 + 4 = 6 seconds, so BDLT = 6 – 4 = 2 seconds,
and BMOT = 1.
0x0870
Busy cadence delta in seconds multiplied by 7200.
0x25F8
BMOT Busy cadence minimum on time in seconds multiplied by 7200.
0x0438
RMTT
RDLT
Ringback cadence minimum total time in seconds multiplied by
7200.
Ringback cadence delta in seconds multiplied by 7200.
0x4650
0xEF10
RMOT Ringback cadence minimum on time in seconds multiplied by 7200. 0x1200
DTWD Window to look for dialtone in seconds multiplied by 1000.
0x1B58
DMOT Minimum dialtone on time in seconds multiplied by 7200.
0x2D00
PD0 Number of pulses to dial 0.
0x000A
PD1 Number of pulses to dial 1.
0x0001
PD2 Number of pulses to dial 2.
0x0002
PD3 Number of pulses to dial 3.
0x0003
PD4 Number of pulses to dial 4.
0x0004
PD5 Number of pulses to dial 5.
0x0005
PD6 Number of pulses to dial 6.
0x0006
PD7 Number of pulses to dial 7.
0x0007
PD8 Number of pulses to dial 8.
0x0008
PD9 Number of pulses to dial 9.
0x0009
PDBT Pulse dial break time (ms units).
0x003D
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Rev. 0.9