SI2493-C-FT Silicon Laboratories Inc, SI2493-C-FT Datasheet - Page 83

• 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

3.3.21. U4E (Pre-dial Delay Time Register)
U4E sets the delay time between the ATD command
carriage return and when the modem goes off-hook and
starts dialing (either tone or pulse - see Table 43). This
delay establishes the minimum time the modem must
be on-hook prior to going off-hook and dialing. France,
Sweden, Switzerland, and Japan have minimum on-
hook time requirements. The value stored in U4E is the
desired delay minus 100 ms. The 100 ms offset is due
to a delay inherent in the dialing algorithm. The value
stored in the register is a hexadecimal number with ms
units. "3.5.20. Country Dependent Setup" on page 138,
contains information about country-specific values for
this register.
3.3.22. U4F (Flash Hook Time Register)
U4F sets the time the modem goes on-hook as a result
of a “!” or ”&” dial modifier (flash hook). The value stored
in the register is a hexadecimal number with ms units
(see Table 44).
3.3.23. U50–U51 (Loop Current Debounce
U50 (LCDN) sets the loop current debounce on-time,
and U51 (LCDF) sets the loop current debounce off-
time (see Table 45). Loop current debounce is used in
Register
Register
Register
Register
U4E
U4F
U50
U51
U52
Registers)
PRDD
Name
Name
Name
LCDN
Name
XMTL
LCDF
FHT
Pre-dial delay-time after ATD command that modem waits to dial (ms
units). The Si2493/57/34/15/04 stays on-hook during this time.
Flash Hook Time (ms units).
Loop current debounce on time (ms units).
Loop current debounce off time (ms units).
Transmit level adjust (1 dB units).
Table 45. Loop Current Debounce Registers
Table 43. Pre-Dial Delay Timer Register
Table 44. Flash Hook Time Register
Table 46. Transmit Level Register
Rev. 0.9
Description
Description
Description
Description
cases where the presence or absence of loop current
must be determined prior to taking some action. For
example, it may be desirable or required to verify the
presence of loop current prior to dialing. The loop
current debounce on-time, LCDN, is used to program a
delay in measuring loop current after the modem goes
off-hook to ensure the loop current is stable prior to the
measurement. LCDN is used in conjunction with
U4D[10] (CLPD) and U4D[0] (LCN). Loop current
debounce off-time, LCDF, is used in conjunction with
LCN to delay the modem going on-hook if loop current
is interrupted during a connection. The values stored in
the registers are hexadecimal numbers with ms units.
The default value for LCDN is 350 ms. The default value
for LCDF is 200 ms. The range of values for these
registers is 0–65535 in ms units.
3.3.24. U52 (Transmit Level Register)
U52 (XMTL)
appearing on a 600 Ω line. (See Table 46.) The default
value of 0x0000 results in a –9.85 dBm transmit level.
U52 can be used to decrease this level in 1 dBm units to
the minimum modem receive threshold of –48 dBm with
a register value of 0x0026.
adjusts
the
modem
transmit
AN93
Default
Default
0x01F4
Default
0x015E
0x00C8
Default
0x0000
0x0000
level
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